You are here

Kwatra, Madan Mohan

Overview:

The focus of this laboratory is on signaling through G protein-coupled receptors and clinical proteomics. These goals are currently being realized through three major projects: (1) Mechanism of signal transduction through substance P receptor in human glioblastomas; (2) Effect of age and diabetes on G protein-coupled receptors in human heart; and (3) Molecular basis of postoperative delirium in the elderly. Our studies use state-of-the-art techniques in protein biochemistry and molecular biology including DNA microarrays. A major goal of project #3 is to identify biomarkers of delirium in plasma using a proteomic approach including analyses by 2D-gel electrophoresis, mass spectrometry,SELDI/TOF (protein-chip), and protein microarrays.

Positions:

Associate Professor in Anesthesiology

Anesthesiology
School of Medicine

Associate Professor in Psychiatry and Behavioral Sciences

Psychiatry & Behavioral Sciences
School of Medicine

Associate Professor of Pharmacology & Cancer Biology

Pharmacology & Cancer Biology
School of Medicine

Member of the Duke Cancer Institute

Duke Cancer Institute
School of Medicine

Education:

Ph.D. 1977

Ph.D. — University of Montreal (Canada)

Grants:

Organization and Function of Cellular Structure

Administered By
Basic Science Departments
AwardedBy
National Institutes of Health
Role
Mentor
Start Date
July 01, 1975
End Date
June 30, 2020

Pharmacological Sciences Training Program

Administered By
Pharmacology & Cancer Biology
AwardedBy
National Institutes of Health
Role
Participating Faculty Member
Start Date
July 01, 1975
End Date
June 30, 2020

Evaluation of VAL-083, either alone or in combination with other agents, for its activity inhibition of glioblastoma subtypes (personalized drug development)

Administered By
Anesthesiology
AwardedBy
DelMar Pharmaceuticals, Inc.
Role
Principal Investigator
Start Date
April 14, 2017
End Date
April 30, 2020

Pharmacology Industry Internships for Ph.D. Students

Administered By
Pharmacology & Cancer Biology
AwardedBy
American Society for Pharmacology and Experimental Therapeutics
Role
Participating Faculty Member
Start Date
January 01, 2017
End Date
December 31, 2019

Glioblastoma model research

Administered By
Anesthesiology
AwardedBy
The Miami Foundation
Role
Principal Investigator
Start Date
November 01, 2017
End Date
October 31, 2019

Evaluation of novel anti-cancer agents, either alone or in combination, for activity against glioblastoma subtypes: a personalized medicine approach

Administered By
Anesthesiology
AwardedBy
Genzada Pharmaceuticals, LLC
Role
Principal Investigator
Start Date
May 08, 2017
End Date
June 30, 2019

Heterogeneity of EGFRvIII-positive glioblastoma and their sensitivity to AZD9291 (Osimertinib)

Administered By
Anesthesiology
AwardedBy
Musella Foundation For Brain Tumor Research & Information, Inc
Role
Principal Investigator
Start Date
May 15, 2018
End Date
August 15, 2018

Curtana Pharmacueticals Sponsored Research Agreement

Administered By
Anesthesiology
AwardedBy
Curtana Pharmaceuticals, Inc.
Role
Principal Investigator
Start Date
December 16, 2016
End Date
June 30, 2017

Evaluation of AZD9291 in Glioblastoma patients with activated EGFR

Administered By
Anesthesiology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
August 01, 2015
End Date
November 30, 2016

Targeting GBMs with Activated EGFR with third-generation, brain-penetrating AZD9291

Administered By
Anesthesiology
AwardedBy
Musella Foundation For Brain Tumor Research & Information, Inc
Role
Principal Investigator
Start Date
June 01, 2016
End Date
August 31, 2016

Summer Research fellowship for two undergraduate Pre-Med Students

Administered By
Anesthesiology
AwardedBy
Musella Foundation For Brain Tumor Research & Information, Inc
Role
Principal Investigator
Start Date
June 01, 2014
End Date
June 30, 2015

Truncated NK1R in GBM: Pharmacology and Relationship with Patient Survival

Administered By
Anesthesiology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
July 01, 2012
End Date
June 30, 2015

Isolation of stem cells from glioblastoma xenografts with activated EGFR

Administered By
Anesthesiology
AwardedBy
Musella Foundation For Brain Tumor Research & Information, Inc
Role
Principal Investigator
Start Date
January 01, 2014
End Date
December 31, 2014

Molecular Basis of Postoperative Delirium in the Elderly

Administered By
Anesthesiology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
January 15, 2003
End Date
June 30, 2010

Aging And G Protein Coupled Receptors In Human Heart

Administered By
Anesthesiology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
September 01, 1998
End Date
August 31, 2006

Beta Adrenoceptors During Cardiopulmonary Bypass

Administered By
Anesthesiology, Cardiothoracic
AwardedBy
National Institutes of Health
Role
Co Investigator
Start Date
January 01, 1997
End Date
December 31, 2002

Function Of Human Substance P Receptor

Administered By
Anesthesiology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
July 01, 1995
End Date
May 31, 2001

Desensitization Of B-Adrenoceptors During Cardiopulmonary

Administered By
Anesthesiology, Cardiothoracic
AwardedBy
National Institutes of Health
Role
Co-Principal Investigator
Start Date
January 01, 1997
End Date
December 31, 1999

Function Of Human Substances P Receptor

Administered By
Anesthesiology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
July 01, 1995
End Date
May 31, 1999

Function Of Substance P Receptor

Administered By
Anesthesiology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
July 01, 1995
End Date
May 31, 1999

Molecular Characterization Of Human Alc-Adrenergic Recept

Administered By
Anesthesiology, Cardiothoracic
AwardedBy
National Institutes of Health
Role
Co-Principal Investigator
Start Date
March 01, 1996
End Date
February 28, 1999

Transcriptional Regulation Of Human 1a-Adrenoceptors

Administered By
Anesthesiology, Cardiothoracic
AwardedBy
National Institutes of Health
Role
Co-Principal Investigator
Start Date
March 01, 1996
End Date
February 28, 1999

Excitatory Amino Acids In Ovine Fetal Brain Injury

Administered By
Anesthesiology, Women's
AwardedBy
National Institutes of Health
Role
Co-Principal Investigator
Start Date
October 01, 1996
End Date
December 31, 1998

Aging And G Protein-Coupled Receptor Signaling In Human

Administered By
Anesthesiology
AwardedBy
National Institutes of Health
Role
Principal Investigator
Start Date
September 30, 1996
End Date
September 29, 1997
Show More

Publications:

Effects of neuroimmune axis modulation by aprepitant on antipruritic and global disease severity in patients with cutaneous T-cell lymphoma.

Authors
Kwatra, SG; Boozalis, E; Kwatra, MM
MLA Citation
Kwatra, SG, Boozalis, E, and Kwatra, MM. "Effects of neuroimmune axis modulation by aprepitant on antipruritic and global disease severity in patients with cutaneous T-cell lymphoma." The British Journal of Dermatology 178.5 (May 2018): 1221-1222. (Letter)
PMID
29352478
Source
epmc
Published In
The British Journal of Dermatology
Volume
178
Issue
5
Publish Date
2018
Start Page
1221
End Page
1222
DOI
10.1111/bjd.16363

A Rational Approach to Target the Epidermal Growth Factor Receptor in Glioblastoma.

Glioblastoma (GBM) is a deadly brain cancer, and all attempts to control it have failed so far. However, the future looks bright, as we now know the molecular landscape of GBM through the work of The Cancer Genome Atlas (TCGA) program. GBMs exhibit significant inter- and intratumoral heterogeneity, and to control this type of tumor, a personalized approach is required. One target, whose gene is amplified and mutated in a large number of GBMs, is the epidermal growth factor receptor (EGFR). But all attempts to target it have been unsuccessful. We attribute the reason for this failure to the molecular heterogeneity of EGFR in GBM, as well as to the poor brain penetration of previously tested EGFR-Tyrosine Kinase Inhibitors (EGFR-TKIs). In this review, we discuss the molecular heterogeneity of EGFR and provide rational preclinical and clinical guidelines for testing AZD9291, a third generation, irreversible EGFR-TKI with both a high affinity for EGFRvIII and excellent brain penetration.

Authors
Kwatra, MM
MLA Citation
Kwatra, MM. "A Rational Approach to Target the Epidermal Growth Factor Receptor in Glioblastoma." Current Cancer Drug Targets 17.3 (January 2017): 290-296. (Review)
PMID
28029074
Source
epmc
Published In
Current Cancer Drug Targets
Volume
17
Issue
3
Publish Date
2017
Start Page
290
End Page
296
DOI
10.2174/1568009616666161227091522

Aprepitant for the Treatment of Chronic Refractory Pruritus.

Chronic pruritus is a difficult condition to treat and is associated with several comorbidities, including insomnia, depression, and decreased quality of life. Treatment for chronic itch includes corticosteroids, antihistamines, and systemic therapies such as naltrexone, gabapentin, UV light therapy, and immunomodulatory treatments, including azathioprine, methotrexate, and cellcept. However, some patients still remain refractory to conventional therapy. Aprepitant is a neurokinin-1 receptor antagonist approved for the prevention of chemotherapy-induced and postoperative nausea and vomiting (CINV, PONV). Recently, aprepitant has demonstrated effectiveness in several case series and open label trials in relieving pruritus for patients refractory to other treatments. Patients with pruritus associated with Sézary syndrome, mycosis fungoides, lung adenocarcinoma, breast carcinoma, sarcomas, metastatic solid tumors, chronic kidney disease, hyperuricemia, iron deficiency, brachioradial pruritus, and Hodgkin's lymphoma have experienced considerable symptom relief with short-term use of aprepitant (up to two weeks). Due to differences in reporting and evaluation of drug effects, the mechanism of aprepitant's role is difficult to understand based on the current literature. Herein, we evaluate aprepitant's antipruritic effects and discuss its mechanism of action and adverse effects. We propose that aprepitant is an alternative for patients suffering from pruritus who do not obtain enough symptom relief from conventional therapy.

Authors
He, A; Alhariri, JM; Sweren, RJ; Kwatra, MM; Kwatra, SG
MLA Citation
He, A, Alhariri, JM, Sweren, RJ, Kwatra, MM, and Kwatra, SG. "Aprepitant for the Treatment of Chronic Refractory Pruritus." BioMed research international 2017 (January 2017): 4790810-. (Review)
PMID
29057261
Source
epmc
Published In
Biomed Research International
Volume
2017
Publish Date
2017
Start Page
4790810
DOI
10.1155/2017/4790810

Association between Serum IGF-I levels and Postoperative Delirium in Elderly Subjects Undergoing Elective Knee Arthroplasty.

Evidence is mixed for an association between serum insulin-like growth factor-I (IGF-I) levels and postoperative delirium (POD). The current study assessed preoperative serum IGF-I levels as a predictor of incident delirium in non-demented elderly elective knee arthroplasty patients. Preoperative serum levels of total IGF-I were measured using a commercially available Human IGF-I ELISA kit. POD incidence and severity were determined using DSM-IV criteria and the Delirium Rating Scale-Revised-98 (DRS-R98), respectively. Median IGF-I levels in delirious (62.6 ng/ml) and non-delirious groups (65.9 ng/ml) were not significantly different (p = 0.141). The ratio (95% CI) of geometric means, D/ND, was 0.86 (0.70, 1.06). The Hodges-Lehmann median difference estimate was 7.23 ng/mL with 95% confidence interval (-2.32, 19.9). In multivariate logistic regression analysis IGF-I level was not a significant predictor of incident POD after correcting for medical comorbidities. IGF-I levels did not correlate with DRS-R98 scores for delirium severity. In conclusion, we report no evidence of association between serum IGF-I levels and incidence of POD, although the sample size was inadequate for a conclusive study. Further efforts to investigate IGF-I as a delirium risk factor in elderly should address comorbidities and confounders that influence IGF-I levels.

Authors
Yen, TE; Allen, JC; Rivelli, SK; Patterson, SC; Metcalf, MR; Flink, BJ; Mirrakhimov, AE; Lagoo, SA; Vail, TP; Young, CC; Moon, RE; Trzepacz, PT; Kwatra, MM
MLA Citation
Yen, TE, Allen, JC, Rivelli, SK, Patterson, SC, Metcalf, MR, Flink, BJ, Mirrakhimov, AE, Lagoo, SA, Vail, TP, Young, CC, Moon, RE, Trzepacz, PT, and Kwatra, MM. "Association between Serum IGF-I levels and Postoperative Delirium in Elderly Subjects Undergoing Elective Knee Arthroplasty." Scientific reports 6 (February 5, 2016): 20736-.
PMID
26846868
Source
epmc
Published In
Scientific Reports
Volume
6
Publish Date
2016
Start Page
20736
DOI
10.1038/srep20736

Proteomic profiling of patient-derived glioblastoma xenografts identifies a subset with activated EGFR: implications for drug development.

The development of drugs to inhibit glioblastoma (GBM) growth requires reliable pre-clinical models. To date, proteomic level validation of widely used patient-derived glioblastoma xenografts (PDGX) has not been performed. In the present study, we characterized 20 PDGX models according to subtype classification based on The Cancer Genome Atlas criteria, TP53, PTEN, IDH 1/2, and TERT promoter genetic analysis, EGFR amplification status, and examined their proteomic profiles against those of their parent tumors. The 20 PDGXs belonged to three of four The Cancer Genome Atlas subtypes: eight classical, eight mesenchymal, and four proneural; none neural. Amplification of EGFR gene was observed in 9 of 20 xenografts, and of these, 3 harbored the EGFRvIII mutation. We then performed proteomic profiling of PDGX, analyzing expression/activity of several proteins including EGFR. Levels of EGFR phosphorylated at Y1068 vary considerably between PDGX samples, and this pattern was also seen in primary GBM. Partitioning of 20 PDGX into high (n = 5) and low (n = 15) groups identified a panel of proteins associated with high EGFR activity. Thus, PDGX with high EGFR activity represent an excellent pre-clinical model to develop therapies for a subset of GBM patients whose tumors are characterized by high EGFR activity. Further, the proteins found to be associated with high EGFR activity can be monitored to assess the effectiveness of targeting EGFR. The development of drugs to inhibit glioblastoma (GBM) growth requires reliable pre-clinical models. We validated proteomic profiles using patient-derived glioblastoma xenografts (PDGX), characterizing 20 PDGX models according to subtype classification based on The Cancer Genome Atlas (TCGA) criteria, TP53, PTEN, IDH 1/2, and TERT promoter genetic analysis, EGFR amplification status, and examined their proteomic profiles against those of their parent tumors. Proteins found to be associated with high EGFR activity represent potential biomarkers for GBM monitoring.

Authors
Brown, KE; Chagoya, G; Kwatra, SG; Yen, T; Keir, ST; Cooter, M; Hoadley, KA; Rasheed, A; Lipp, ES; Mclendon, R; Ali-Osman, F; Bigner, DD; Sampson, JH; Kwatra, MM
MLA Citation
Brown, KE, Chagoya, G, Kwatra, SG, Yen, T, Keir, ST, Cooter, M, Hoadley, KA, Rasheed, A, Lipp, ES, Mclendon, R, Ali-Osman, F, Bigner, DD, Sampson, JH, and Kwatra, MM. "Proteomic profiling of patient-derived glioblastoma xenografts identifies a subset with activated EGFR: implications for drug development." Journal of Neurochemistry 133.5 (June 2015): 730-738.
PMID
25598002
Source
epmc
Published In
Journal of Neurochemistry
Volume
133
Issue
5
Publish Date
2015
Start Page
730
End Page
738
DOI
10.1111/jnc.13032

Proteomic profiling of patient-derived glioblastoma xenografts identifies a subset with activated EGFR: Implications for drug development

© 2015 International Society for Neurochemistry.The development of drugs to inhibit glioblastoma (GBM) growth requires reliable pre-clinical models. To date, proteomic level validation of widely used patient-derived glioblastoma xenografts (PDGX) has not been performed. In the present study, we characterized 20 PDGX models according to subtype classification based on The Cancer Genome Atlas criteria, TP53, PTEN, IDH 1/2, and TERT promoter genetic analysis, EGFR amplification status, and examined their proteomic profiles against those of their parent tumors. The 20 PDGXs belonged to three of four The Cancer Genome Atlas subtypes: eight classical, eight mesenchymal, and four proneural; none neural. Amplification of EGFR gene was observed in 9 of 20 xenografts, and of these, 3 harbored the EGFRvIII mutation. We then performed proteomic profiling of PDGX, analyzing expression/activity of several proteins including EGFR. Levels of EGFR phosphorylated at Y1068 vary considerably between PDGX samples, and this pattern was also seen in primary GBM. Partitioning of 20 PDGX into high (n = 5) and low (n = 15) groups identified a panel of proteins associated with high EGFR activity. Thus, PDGX with high EGFR activity represent an excellent pre-clinical model to develop therapies for a subset of GBM patients whose tumors are characterized by high EGFR activity. Further, the proteins found to be associated with high EGFR activity can be monitored to assess the effectiveness of targeting EGFR.

Authors
Brown, KE; Chagoya, G; Kwatra, SG; Yen, T; Keir, ST; Cooter, M; Hoadley, KA; Rasheed, A; Lipp, ES; McLendon, R; Ali-Osman, F; Bigner, DD; Sampson, JH; Kwatra, MM
MLA Citation
Brown, KE, Chagoya, G, Kwatra, SG, Yen, T, Keir, ST, Cooter, M, Hoadley, KA, Rasheed, A, Lipp, ES, McLendon, R, Ali-Osman, F, Bigner, DD, Sampson, JH, and Kwatra, MM. "Proteomic profiling of patient-derived glioblastoma xenografts identifies a subset with activated EGFR: Implications for drug development." Journal of Neurochemistry 133.5 (2015): 730-738.
Source
scival
Published In
Journal of Neurochemistry
Volume
133
Issue
5
Publish Date
2015
Start Page
730
End Page
738
DOI
10.1111/jnc.13032

Abstract 838: Establishment, identification and treatment data of TCGA glioblatoma xenograft subtypes

Authors
Keir, ST; Rasheed, BA; Hoadley, KA; Roskoski, MA; Gasinski, D; Killela, PJ; Yan, H; Kwatra, MM; Friedman, HS; Bigner, DD
MLA Citation
Keir, ST, Rasheed, BA, Hoadley, KA, Roskoski, MA, Gasinski, D, Killela, PJ, Yan, H, Kwatra, MM, Friedman, HS, and Bigner, DD. "Abstract 838: Establishment, identification and treatment data of TCGA glioblatoma xenograft subtypes." October 1, 2014.
Source
crossref
Published In
Cancer Research
Volume
74
Issue
19 Supplement
Publish Date
2014
Start Page
838
End Page
838
DOI
10.1158/1538-7445.AM2014-838

Patient-derived xenografts mirror the proteomic profile of human glioblastoma: implications for personalized drug development.

(blind field).

Authors
Kwatra, MM; Brown, KE; Chagoya, G; Keir, ST; Bigner, DD; Sampson, JH
MLA Citation
Kwatra, MM, Brown, KE, Chagoya, G, Keir, ST, Bigner, DD, and Sampson, JH. "Patient-derived xenografts mirror the proteomic profile of human glioblastoma: implications for personalized drug development." Neuro Oncol 16 Suppl 3 (July 2014): iii38-.
PMID
25165310
Source
pubmed
Published In
Neuro Oncol
Volume
16 Suppl 3
Publish Date
2014
Start Page
iii38
DOI
10.1093/neuonc/nou208.57

Obstructive sleep apnea and delirium: exploring possible mechanisms.

INTRODUCTION: Obstructive sleep apnea (OSA) is a medical disorder strongly associated with multiple comorbidities and postoperative complications. Current evidence suggests that OSA disturbs fundamental biochemical processes, leading to low-grade systemic inflammation and oxidative stress. Animal models have shown that OSA may lead to apoptosis of central neurons. In clinical studies, oxygen desaturation index and sleep fragmentation have been shown to be independently associated with cognitive dysfunction. Moreover, in several studies, patients with OSA were shown to have decreased brain activation in multiple brain areas. OSA AND DELIRIUM: The possibility of an association between OSA and delirium has been highlighted in several case reports. The first prospective study of the possible link between apnea and delirium showed that the presence of OSA was independently associated with the occurrence of delirium after knee replacement surgery. CONCLUSIONS: Therefore, we suggest that OSA should be considered as a risk factor for delirium, and clinicians should assess patients for OSA and related risk factors prior to surgery. However, further research is required to shed light on the mechanisms connecting these disorders and on whether the treatment of OSA affects the incidence of delirium.

Authors
Mirrakhimov, AE; Brewbaker, CL; Krystal, AD; Kwatra, MM
MLA Citation
Mirrakhimov, AE, Brewbaker, CL, Krystal, AD, and Kwatra, MM. "Obstructive sleep apnea and delirium: exploring possible mechanisms." Sleep Breath 18.1 (March 2014): 19-29. (Review)
PMID
23584846
Source
pubmed
Published In
Sleep and Breathing
Volume
18
Issue
1
Publish Date
2014
Start Page
19
End Page
29
DOI
10.1007/s11325-013-0846-z

Obstructive sleep apnea and delirium: Exploring possible mechanisms

Introduction: Obstructive sleep apnea (OSA) is a medical disorder strongly associated with multiple comorbidities and postoperative complications. Current evidence suggests that OSA disturbs fundamental biochemical processes, leading to low-grade systemic inflammation and oxidative stress. Animal models have shown that OSA may lead to apoptosis of central neurons. In clinical studies, oxygen desaturation index and sleep fragmentation have been shown to be independently associated with cognitive dy sfunction. Moreover, in several studies, patients with OSA were shown to have decreased brain activation in multiple brain areas. OSA and delirium: The possibility of an association between OSA and delirium has been highlighted in several case reports. The first prospective study of the possible link between apnea and delirium showed that the presence of OSA was independently associated with the occurrence of delirium after knee replacement surgery. Conclusions: Therefore, we suggest that OSA should be considered as a risk factor for delirium, and clinicians should assess patients for OSA and related risk factors prior to surgery. However, further research is required to shed light on the mechanisms connecting these disorders and on whether the treatment of OSA affects the incidence of delirium. © 2013 Springer-Verlag.

Authors
Mirrakhimov, AE; Brewbaker, CL; Krystal, AD; Kwatra, MM
MLA Citation
Mirrakhimov, AE, Brewbaker, CL, Krystal, AD, and Kwatra, MM. "Obstructive sleep apnea and delirium: Exploring possible mechanisms." Sleep and Breathing 18.1 (January 1, 2014): 19-29. (Review)
Source
scopus
Published In
Sleep and Breathing
Volume
18
Issue
1
Publish Date
2014
Start Page
19
End Page
29
DOI
10.1007/s11325-013-0846-z

Revisiting the prehypertension debate: increasing evidence for treatment yet randomized clinical trials are lacking.

In 2009, Blood Pressure featured a debate about whether to treat patients with prehypertension (Kiely et al., Blood Press. 2009;18:300-303; McInnes GT, Blood Press. 2009;18:304-307). Our group supported pharmacotherapy for this condition at that time. Since then, additional evidence linking prehypertension with associated morbidities has emerged. These studies are detailed below and provide further evidence for the treatment of prehypertension.

Authors
Reed, C; Kwatra, SG; Brown, K; Kwatra, MM
MLA Citation
Reed, C, Kwatra, SG, Brown, K, and Kwatra, MM. "Revisiting the prehypertension debate: increasing evidence for treatment yet randomized clinical trials are lacking." Blood Pressure 22.6 (December 2013): 340-343.
PMID
23638979
Source
epmc
Published In
Blood Pressure
Volume
22
Issue
6
Publish Date
2013
Start Page
340
End Page
343
DOI
10.3109/08037051.2013.787705

Propofol and the risk of delirium: exploring the anticholinergic properties of propofol.

Delirium is a common pathologic event in both medical and surgical patients. It is essential to note that patients who develop delirium have worse long term outcomes. The etiology and pathogenesis of delirium are extremely complex and not entirely understood. Certain medications classes are implicated in delirium. For example, medications targeting muscarinic acetylcholine receptors are well known to be associated with delirium and altered mentation. Propofol is a medication commonly used in anesthesiology practice and sedation in intubated patients. In vitro studies provided evidence that propofol actively interacts with muscarinic acetylcholine receptors. Additionally, some, but not all clinical studies demonstrated that propofol led to delirium. Therefore, future prospective studies investigating the use of propofol and delirium occurrence are of paramount importance. These studies should adjust for such common confounders as patients' demographics and age, comorbid conditions, use of other medications, type of surgery, baseline cognitive status, etc. Another important task would be to research the susceptibility for propofol-related delirium. By studying these critical questions, we will gain additional insights into the complex etiology and pathobiology of delirium in addition to a better understanding of the pharmacology of propofol.

Authors
Brown, KE; Mirrakhimov, AE; Yeddula, K; Kwatra, MM
MLA Citation
Brown, KE, Mirrakhimov, AE, Yeddula, K, and Kwatra, MM. "Propofol and the risk of delirium: exploring the anticholinergic properties of propofol." Medical Hypotheses 81.4 (October 2013): 536-539.
PMID
23891036
Source
epmc
Published In
Medical Hypotheses
Volume
81
Issue
4
Publish Date
2013
Start Page
536
End Page
539
DOI
10.1016/j.mehy.2013.06.027

Delirium after cardiac surgery: have we overlooked obstructive sleep apnea?

Obstructive sleep apnea is common in patients with cardiovascular disease. It is well known that cardiac surgery is a risk factor for delirium. Researchers have shown that obstructive sleep apnea is an independent risk factor for the occurrence of delirium. In this manuscript we speculate on how obstructive sleep apnea may increase the risk of delirium in patients with cardiac surgery. If this is found to be confirmed, we would have another target through which we can decrease the risk of delirium in this population.

Authors
Mirrakhimov, AE; Yen, T; Kwatra, MM
MLA Citation
Mirrakhimov, AE, Yen, T, and Kwatra, MM. "Delirium after cardiac surgery: have we overlooked obstructive sleep apnea?." Medical Hypotheses 81.1 (July 2013): 15-20.
PMID
23618612
Source
epmc
Published In
Medical Hypotheses
Volume
81
Issue
1
Publish Date
2013
Start Page
15
End Page
20
DOI
10.1016/j.mehy.2013.03.033

Tachykinin/Substance P/Neurokinin-1 Receptors

© 2013 Elsevier Inc. All rights reserved. Tachykinins are small peptides, found in both vertebrates and invertebrates, which regulate many physiological processes. They are distributed mainly in the central nervous system, but are also important regulators of contractility in vascular smooth muscle and many areas of the gastrointestinal tract. Tachykinins (meaning fast acting) are characterized by an amidated C-terminus containing the amino acids F-X-G-L-M-NH 2 , where X is a hydrophobic amino acid residue. Tachykinins act through receptors that are members of the G-protein-coupled receptor superfamily. The best-known mammalian tachykinin is substance P (SP), a peptide of 11 amino acids. The preferred receptor for SP, neurokinin-1 receptor (NK1R; also known as substance P receptor), occurs as a full-length receptor and in a truncated form, which lacks the carboxyl-tail. The carboxyl tail of NK1R plays an important role in receptor desensitization; therefore, the truncated form of NK1R differs from full-length NK1R in its interactions with proteins involved in receptor desensitization. Finally, NK1R has an important role in pain and in several human disorders, including emesis, depression, and glioblastoma.

Authors
Goldsmith, LE; Kwatra, MM
MLA Citation
Goldsmith, LE, and Kwatra, MM. "Tachykinin/Substance P/Neurokinin-1 Receptors." Encyclopedia of Biological Chemistry: Second Edition. February 15, 2013. 360-365.
Source
scopus
Publish Date
2013
Start Page
360
End Page
365
DOI
10.1016/B978-0-12-378630-2.00364-9

Propofol And The Risk Of Delirium: Exploring The Anticholinergic Properties Of Propofol

Delirium is a common pathologic event in both medical and surgical patients. It is essential to note that patients who develop delirium have worse long term outcomes. The etiology and pathogenesis of delirium are extremely complex and not entirely understood. Certain medications classes are implicated in delirium. For example, medications targeting muscarinic acetylcholine receptors are well known to be associated with delirium and altered mentation. Propofol is a medication commonly used in anesthesiology practice and sedation in intubated patients. In vitro studies provided evidence that propofol actively interacts with muscarinic acetylcholine receptors. Additionally, some, but not all clinical studies demonstrated that propofol led to delirium. Therefore, future prospective studies investigating the use of propofol and delirium occurrence are of paramount importance. These studies should adjust for such common confounders as patients' demographics and age, comorbid conditions, use of other medications, type of surgery, baseline cognitive status, etc. Another important task would be to research the susceptibility for propofol-related delirium. By studying these critical questions, we will gain additional insights into the complex etiology and pathobiology of delirium in addition to a better understanding of the pharmacology of propofol. © 2013 Elsevier Ltd.

Authors
Brown, KE; Mirrakhimov, AE; Yeddula, K; Kwatra, MM
MLA Citation
Brown, KE, Mirrakhimov, AE, Yeddula, K, and Kwatra, MM. "Propofol And The Risk Of Delirium: Exploring The Anticholinergic Properties Of Propofol." Medical Hypotheses 81.4 (2013): 536-539.
Source
scival
Published In
Medical Hypotheses
Volume
81
Issue
4
Publish Date
2013
Start Page
536
End Page
539
DOI
10.1016/j.mehy.2013.06.027

Delirium after cardiac surgery: Have we overlooked obstructive sleep apnea?

Obstructive sleep apnea is common in patients with cardiovascular disease. It is well known that cardiac surgery is a risk factor for delirium. Researchers have shown that obstructive sleep apnea is an independent risk factor for the occurrence of delirium. In this manuscript we speculate on how obstructive sleep apnea may increase the risk of delirium in patients with cardiac surgery. If this is found to be confirmed, we would have another target through which we can decrease the risk of delirium in this population. © 2013.

Authors
Mirrakhimov, AE; Yen, T; Kwatra, MM
MLA Citation
Mirrakhimov, AE, Yen, T, and Kwatra, MM. "Delirium after cardiac surgery: Have we overlooked obstructive sleep apnea?." Medical Hypotheses 81.1 (2013): 15-20.
Source
scival
Published In
Medical Hypotheses
Volume
81
Issue
1
Publish Date
2013
Start Page
15
End Page
20
DOI
10.1016/j.mehy.2013.03.033

In reply.

Authors
Kwatra, MM; Moon, RE; White, WD; Trzepacz, PT; Rivelli, SK
MLA Citation
Kwatra, MM, Moon, RE, White, WD, Trzepacz, PT, and Rivelli, SK. "In reply." Anesthesiology 117.6 (December 2012): 1392-1393.
PMID
23168432
Source
pubmed
Published In
Anesthesiology
Volume
117
Issue
6
Publish Date
2012
Start Page
1392
End Page
1393
DOI
10.1097/ALN.0b013e3182735c0f

Insulin-like growth factor 1 and delirium.

Authors
Motosko, C; Brown, K; Kwatra, M
MLA Citation
Motosko, C, Brown, K, and Kwatra, M. "Insulin-like growth factor 1 and delirium." International Psychogeriatrics 24.11 (November 2012): 1872-null. (Letter)
PMID
22717314
Source
epmc
Published In
International Psychogeriatrics
Volume
24
Issue
11
Publish Date
2012
Start Page
1872
DOI
10.1017/s1041610212000464

NEUROKININ-1 RECEPTOR: A POTENTIAL TARGET TO INHIBIT PEDIATRIC GLIOBLASTOMAS

Authors
Brown, KE; Keir, ST; Sampson, JH; Bigner, DD; Kwatra, MM
MLA Citation
Brown, KE, Keir, ST, Sampson, JH, Bigner, DD, and Kwatra, MM. "NEUROKININ-1 RECEPTOR: A POTENTIAL TARGET TO INHIBIT PEDIATRIC GLIOBLASTOMAS." October 2012.
Source
wos-lite
Published In
Neuro Oncology
Volume
14
Publish Date
2012
Start Page
17
End Page
18

Obstructive sleep apnea and incidence of postoperative delirium after elective knee replacement in the nondemented elderly.

Postoperative delirium, a common complication in the elderly, can occur following any type of surgery and is associated with increased morbidity and mortality; it may also be associated with subsequent cognitive problems. Effective therapy for postoperative delirium remains elusive because the causative factors of delirium are likely multiple and varied.Patients 65 yr or older undergoing elective knee arthroplasty were prospectively evaluated for postoperative Diagnostic and Statistical Manual of Mental Disorders-IV delirium. Exclusion criteria included dementia, mini-mental state exam score less than 24, delirium, clinically significant central nervous system/neurologic disorder, current alcoholism, or any serious psychiatric disorder. Delirium was assessed on postoperative days 2 and 3 using standardized scales. Patients' preexisting medical conditions were obtained from medical charts. The occurrence of obstructive sleep apnea was confirmed by contacting patients to check their polysomnography records. Data were analyzed using Pearson chi-square or Wilcoxon rank sum tests and multiple logistic regressions adjusted for effects of covariates.Of 106 enrolled patients, 27 (25%) developed postoperative delirium. Of the 15 patients with obstructive sleep apnea, eight (53%) experienced postoperative delirium, compared with 19 (20%) of the patients without obstructive sleep apnea (P = 0.0123, odds ratio: 4.3). Obstructive sleep apnea was the only statistically significant predictor of postoperative delirium in multivariate analyses.This is the first prospective study employing validated measures of delirium to identify an association between preexisting obstructive sleep apnea and postoperative delirium.

Authors
Flink, BJ; Rivelli, SK; Cox, EA; White, WD; Falcone, G; Vail, TP; Young, CC; Bolognesi, MP; Krystal, AD; Trzepacz, PT; Moon, RE; Kwatra, MM
MLA Citation
Flink, BJ, Rivelli, SK, Cox, EA, White, WD, Falcone, G, Vail, TP, Young, CC, Bolognesi, MP, Krystal, AD, Trzepacz, PT, Moon, RE, and Kwatra, MM. "Obstructive sleep apnea and incidence of postoperative delirium after elective knee replacement in the nondemented elderly." Anesthesiology 116.4 (April 2012): 788-796.
PMID
22337162
Source
epmc
Published In
Anesthesiology
Volume
116
Issue
4
Publish Date
2012
Start Page
788
End Page
796
DOI
10.1097/ALN.0b013e31824b94fc

Prehypertension: to treat or not to treat should no longer be the question.

Authors
Kwatra, SG; Kiely, AE; Kwatra, MM
MLA Citation
Kwatra, SG, Kiely, AE, and Kwatra, MM. "Prehypertension: to treat or not to treat should no longer be the question." Hypertension 59.4 (April 2012): e27-. (Letter)
PMID
22371356
Source
pubmed
Published In
Hypertension
Volume
59
Issue
4
Publish Date
2012
Start Page
e27
DOI
10.1161/HYPERTENSIONAHA.111.190678

Prevention of intraoperative awareness.

Authors
Kwatra, MM
MLA Citation
Kwatra, MM. "Prevention of intraoperative awareness." The New England Journal of Medicine 365.21 (November 2011): 2033-null. (Letter)
PMID
22111726
Source
epmc
Published In
The New England Journal of Medicine
Volume
365
Issue
21
Publish Date
2011
Start Page
2033
DOI
10.1056/nejmc1110999

TRUNCATED NEUROKININ 1 RECEPTOR: EXPRESSION IN PRIMARY GLIOBLASTOMAS AND RELATIONSHIP WITH PATIENT SURVIVAL

Authors
Kwatra, MM; Porter, TM; Brown, KE; Herndon, JE; Bigner, DD
MLA Citation
Kwatra, MM, Porter, TM, Brown, KE, Herndon, JE, and Bigner, DD. "TRUNCATED NEUROKININ 1 RECEPTOR: EXPRESSION IN PRIMARY GLIOBLASTOMAS AND RELATIONSHIP WITH PATIENT SURVIVAL." NEURO-ONCOLOGY 13 (November 2011): 82-82.
Source
wos-lite
Published In
Neuro Oncology
Volume
13
Publish Date
2011
Start Page
82
End Page
82

DIFFERENTIAL EXPRESSION OF FULL-LENGTH AND TRUNCATED NEUROKININ 1 RECEPTORS IN GLIOBLASTOMA CELLS

Authors
Kwatra, MM
MLA Citation
Kwatra, MM. "DIFFERENTIAL EXPRESSION OF FULL-LENGTH AND TRUNCATED NEUROKININ 1 RECEPTORS IN GLIOBLASTOMA CELLS." November 2010.
Source
wos-lite
Published In
Neuro Oncology
Volume
12
Publish Date
2010
Start Page
18
End Page
18

Low expression of alpha-adrenergic receptors in the aging human heart.

Authors
Kwatra, SG; Goldsmith, LE; White, WD; Lin, SS; Kwatra, MM
MLA Citation
Kwatra, SG, Goldsmith, LE, White, WD, Lin, SS, and Kwatra, MM. "Low expression of alpha-adrenergic receptors in the aging human heart." Journal of the American Geriatrics Society 58.1 (January 2010): 210-212. (Letter)
PMID
20122076
Source
epmc
Published In
Journal of the American Geriatrics Society
Volume
58
Issue
1
Publish Date
2010
Start Page
210
End Page
212
DOI
10.1111/j.1532-5415.2009.02659.x

Flaws in the serum anticholinergic activity assay: implications for the study of delirium.

Authors
Cox, EA; Kwatra, SG; Shetty, S; Kwatra, MM
MLA Citation
Cox, EA, Kwatra, SG, Shetty, S, and Kwatra, MM. "Flaws in the serum anticholinergic activity assay: implications for the study of delirium." J Am Geriatr Soc 57.9 (September 2009): 1707-1708. (Letter)
PMID
19895433
Source
pubmed
Published In
Journal of the American Geriatrics Society
Volume
57
Issue
9
Publish Date
2009
Start Page
1707
End Page
1708
DOI
10.1111/j.1532-5415.2009.02411.x

A constitutively active form of neurokinin 1 receptor and neurokinin 1 receptor-mediated apoptosis in glioblastomas.

Previous studies have shown that neurokinin 1 receptor (NK1R) occurs naturally in human glioblastomas and its stimulation causes cell proliferation. In the present study we show that stimulation of NK1R in human U373 glioblastoma cells by substance P increases Akt phosphorylation by 2.5-fold, with an EC(50) of 57 nM. Blockade of NK1R lowers basal phosphorylation of Akt, indicating the presence of a constitutively active form of NK1R; similar results are seen in U251 MG and DBTRG-05 glioblastoma cells. Linkage of NK1R to Akt implicates NK1R in apoptosis of glioblastoma cells. Indeed, treatment of serum-starved U373 cells with substance P reduces apoptosis by 53 +/- 1% (p < 0.05), and treatment with NK1R antagonist L-733,060 increases apoptosis by 64 +/- 16% (p < 0.01). Further, the blockade of NK1R in human glioblastoma cells with L-733,060 causes cleavage of Caspase-3 and proteolysis of poly (ADP-ribose) polymerase. Experiments designed to elucidate the mechanism of NK1R-mediated Akt phosphorylation revealed total involvement of non-receptor tyrosine kinase Src and phosphatidyl-3-kinase, a partial involvement of epidermal growth factor receptor, and no involvement of mitogen-activated protein/extracellular signal-related kinase. Taken together, the results of the present study indicate a key role for NK1R in glioblastoma apoptosis.

Authors
Akazawa, T; Kwatra, SG; Goldsmith, LE; Richardson, MD; Cox, EA; Sampson, JH; Kwatra, MM
MLA Citation
Akazawa, T, Kwatra, SG, Goldsmith, LE, Richardson, MD, Cox, EA, Sampson, JH, and Kwatra, MM. "A constitutively active form of neurokinin 1 receptor and neurokinin 1 receptor-mediated apoptosis in glioblastomas." J Neurochem 109.4 (May 2009): 1079-1086.
PMID
19519779
Source
pubmed
Published In
Journal of Neurochemistry
Volume
109
Issue
4
Publish Date
2009
Start Page
1079
End Page
1086
DOI
10.1111/j.1471-4159.2009.06032.x

Treating prehypertension: medically sound and economically viable.

The 7th Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure provided new guide-lines for the definition and management of hypertension. Notably, a new category-"prehypertension"-was created for intermediate systolic pressures exceeding 120 mmHg, the upper limit of normal, but less than 139 mmHg, the threshold for stage 1 hypertension. The therapeutic consequences of this new classification are not yet clear, but research indicates that prehypertension is an independent risk factor for cardiovascular, cognitive, and renal morbidities as well as diabetes, and statistical data indicate that prehypertension is present in over 30% of US, European, and Asian adults. However, while pharmacotherapy is recommended for hypertension, the use of drugs to control prehypertension is under question. Given the serious health consequences linked with prehypertension, such debates seem misplaced if patient well-being is our priority. While acknowledging the lack of specific randomized controlled trial data on this topic, we suggest that anti-hypertensive therapy be recommended for everyone with prehypertension and address resulting cost-benefit issues.

Authors
Kiely, AE; Kwatra, SG; Kwatra, MM
MLA Citation
Kiely, AE, Kwatra, SG, and Kwatra, MM. "Treating prehypertension: medically sound and economically viable." Blood Press 18.6 (2009): 300-303.
PMID
19958077
Source
pubmed
Published In
Blood Pressure (Informa)
Volume
18
Issue
6
Publish Date
2009
Start Page
300
End Page
303
DOI
10.3109/08037050903444024

Limitations of the anticholinergic risk scale

Authors
Kwatra, M
MLA Citation
Kwatra, M. "Limitations of the anticholinergic risk scale." Archives of Internal Medicine 168.21 (2008): 2386--.
PMID
19029509
Source
scival
Published In
Archives of Internal Medicine
Volume
168
Issue
21
Publish Date
2008
Start Page
2386-
DOI
10.1001/archinte.168.21.2386-a

Selective activation of human atrial Galpha12 and Galpha13 by Galphaq-coupled angiotensin and endothelin receptors.

Galphaq-coupled receptors such as alpha1-adrenergic, angiotensin, and endothelin receptors, play key roles in cardiac physiology. These receptors have also been shown to couple to G proteins of the G12 family, including Galpha12 and Galpha13. In this report, we determined whether these G proteins interact with endothelin, angiotensin, and alpha1-adrenergic receptors in the human heart. We find that these receptors activate cardiac Galpha12 and Galpha13 differentially; endothelin receptors activate only Galpha12 (to 218 +/- 22% of unstimulated levels), angiotensin receptors activate only Galpha13 (to 236 +/- 49% of unstimulated levels), and alpha1-adrenergic receptors activate neither Galpha12 (123 +/- 18% of unstimulated levels) nor Galpha13 (113 +/- 12% of unstimulated levels). Consistent with these data, translocation of guanine nucleotide exchange factor p115RhoGEF, which responds to Galpha13, occurs only after stimulation of angiotensin receptors (shifting from 73 +/- 12% to 41 +/- 10% cytosolic). These differences in the activation of Galpha12 and Galpha13 by Galphaq-coupled receptors may underlie reported differences in the functions of these receptors.

Authors
Kilts, JD; Lin, SS; Lowe, JE; Kwatra, MM
MLA Citation
Kilts, JD, Lin, SS, Lowe, JE, and Kwatra, MM. "Selective activation of human atrial Galpha12 and Galpha13 by Galphaq-coupled angiotensin and endothelin receptors." Journal of Cardiovascular Pharmacology 50.3 (September 2007): 299-303.
PMID
17878759
Source
epmc
Published In
Journal of Cardiovascular Pharmacology
Volume
50
Issue
3
Publish Date
2007
Start Page
299
End Page
303
DOI
10.1097/fjc.0b013e3180a72632

Delirium in older persons.

Authors
Kwatra, MM
MLA Citation
Kwatra, MM. "Delirium in older persons." N Engl J Med 354.23 (June 8, 2006): 2509-2511. (Letter)
PMID
16764059
Source
pubmed
Published In
The New England Journal of Medicine
Volume
354
Issue
23
Publish Date
2006
Start Page
2509
End Page
2511

Prevention of atrial fibrillation following cardiac surgery.

Authors
Kwatra, MM
MLA Citation
Kwatra, MM. "Prevention of atrial fibrillation following cardiac surgery." JAMA 295.19 (May 17, 2006): 2247-2248. (Letter)
PMID
16705100
Source
pubmed
Published In
Jama
Volume
295
Issue
19
Publish Date
2006
Start Page
2247
End Page
2248
DOI
10.1001/jama.295.19.2247-c

Delirium in older persons [11]

Authors
Kwatra, MM
MLA Citation
Kwatra, MM. "Delirium in older persons [11]." New England Journal of Medicine 354.23 (2006): 2510--.
Source
scival
Published In
The New England Journal of Medicine
Volume
354
Issue
23
Publish Date
2006
Start Page
2510-

Signal transduction through substance P receptor in human glioblastoma cells: roles for Src and PKCdelta.

Substance P receptor (SPR), a G protein-coupled receptor (GPCR), is found in human glioblastomas, and has been implicated in their growth. Consistent with a role for SPR in cell growth, activation of SPR in U373 MG human glioblastoma cells leads to the phosphorylation of mitogen-activated protein kinases [extracellular signal-regulated kinase 1 and 2 (ERK1/2)] and stimulation of cell proliferation. The purpose of the present study was to elucidate the pathway through which these actions occur. Using either the epidermal growth factor receptor (EGFR) kinase inhibitor, AG 1478, or a small-interfering RNA (siRNA) directed against human EGFR, we found that transactivation of EGFR by SPR is only marginally involved in SP-dependent ERK1/2 phosphorylation. Src, however, is shown to be a major component of SPR signaling because the Src kinase inhibitor, PP2, and a kinase-dead Src mutant both inhibit SP-dependent ERK1/2 phosphorylation. We also report that SPR stimulates the phosphorylation of protein kinase Cdelta(PKCdelta), and that this stimulation is blocked by PP2. SP-dependent ERK1/2 phosphorylation is also blocked by rottlerin, a PKCdelta inhibitor, and the calcium scavenger, BAPTA/AM. Finally, rottlerin and PP2 were both found to inhibit the growth of several glioblastoma cell lines, underscoring the potential of these agents to block glioblastoma growth.

Authors
Yamaguchi, K; Richardson, MD; Bigner, DD; Kwatra, MM
MLA Citation
Yamaguchi, K, Richardson, MD, Bigner, DD, and Kwatra, MM. "Signal transduction through substance P receptor in human glioblastoma cells: roles for Src and PKCdelta." Cancer Chemother Pharmacol 56.6 (December 2005): 585-593.
PMID
16012865
Source
pubmed
Published In
Cancer Chemotherapy and Pharmacology
Volume
56
Issue
6
Publish Date
2005
Start Page
585
End Page
593
DOI
10.1007/s00280-005-1030-3

G alpha(q)-coupled receptors in human atrium function through protein kinase C epsilon and delta.

Cardiac G alpha(q)-coupled receptors (such as endothelin, angiotensin, and alpha1-adrenergic receptors) mediate cardiac inotropy and chronotropy, as well as the development of hypertrophy. These receptors signal through protein kinase C (PKC), a family of 12 isozymes including PKC alpha, beta I, beta II, gamma, delta, epsilon, theta, eta, lambda, iota, zeta, and mu. Of these PKC isozymes, alpha, beta II, gamma, epsilon, delta, and zeta have been implicated in signaling through cardiac G alpha(q)-coupled receptors in various animal models. However, the profile of which isozymes are activated by a given G alpha(q)-coupled receptor varies among animal species. Thus, these results can not be extrapolated to human heart. In this study, we examine PKC isozymes activated by three different G alpha(q)-coupled receptors in human atrial tissue. Live atrial appendages obtained from the operating room were sliced and treated with agonists of G alpha(q)-coupled receptors, and cellular redistribution of PKC isozymes was examined by immunoblotting. We find that stimulation of G alpha(q)-coupled receptors in human atrium activates PKC epsilon and delta only, under both acute (5 min) and longer (35 min) stimulations. Further, PKC epsilon and delta exhibit distinct subcellular redistribution patterns; while both translocate to the plasma membrane upon G alpha(q) stimulation, PKC delta also redistributes to mitochondria. We conclude that PKC epsilon and delta are the main PKC isozymes involved in G alpha(q)-mediated signaling in human atria.

Authors
Kilts, JD; Grocott, HP; Kwatra, MM
MLA Citation
Kilts, JD, Grocott, HP, and Kwatra, MM. "G alpha(q)-coupled receptors in human atrium function through protein kinase C epsilon and delta." J Mol Cell Cardiol 38.2 (February 2005): 267-276.
PMID
15698833
Source
pubmed
Published In
Journal of Molecular and Cellular Cardiology
Volume
38
Issue
2
Publish Date
2005
Start Page
267
End Page
276
DOI
10.1016/j.yjmcc.2004.11.011

q-coupled receptors in human atrium function through protein kinase C ε and δ

Cardiac Gα q -coupled receptors (such as endothelin, angiotensin, and α 1 -adrenergic receptors) mediate cardiac inotropy and chronotropy, as well as the development of hypertrophy. These receptors signal through protein kinase C (PKC), a family of 12 isozymes including PKC α, βI, βII, γ, δ, ε, θ, η, λ, ι, ζ, and μ. Of these PKC isozymes, α, βII, γ, ε, δ, and ζ have been implicated in signaling through cardiac Gα q -coupled receptors in various animal models. However, the profile of which isozymes are activated by a given Gα q -coupled receptor varies among animal species. Thus, these results can not be extrapolated to human heart. In this study, we examine PKC isozymes activated by three different Gα q -coupled receptors in human atrial tissue. Live atrial appendages obtained from the operating room were sliced and treated with agonists of Gα q -coupled receptors, and cellular redistribution of PKC isozymes was examined by immunoblotting. We find that stimulation of Gα q -coupled receptors in human atrium activates PKC ε and δ only, under both acute (5 min) and longer (35 min) stimulations. Further, PKC ε and δ exhibit distinct subcellular redistribution patterns; while both translocate to the plasma membrane upon Gα q stimulation, PKC δ also redistributes to mitochondria. We conclude that PKC ε and δ are the main PKC isozymes involved in Gα q -mediated signaling in human atria. © 2005 Elsevier Ltd. All rights reserved.

Authors
Kilts, JD; Grocott, HP; Kwatra, MM
MLA Citation
Kilts, JD, Grocott, HP, and Kwatra, MM. "Gαq-coupled receptors in human atrium function through protein kinase C ε and δ." Journal of Molecular and Cellular Cardiology 38.2 (January 1, 2005): 267-276.
Source
scopus
Published In
Journal of Molecular and Cellular Cardiology
Volume
38
Issue
2
Publish Date
2005
Start Page
267
End Page
276
DOI
10.1016/j.yjmcc.2004.11.011

Increased expression of Gi-coupled muscarinic acetylcholine receptor and Gi in atrium of elderly diabetic subjects.

In an ongoing investigation of the effects of age on G protein-coupled receptor signaling in human atrial tissue, we have found that the density of atrial muscarinic acetylcholine receptor (mAChR) increases with age but reaches statistical significance only in patients with diabetes. Moreover, we find that in elderly subjects of similar ages, those with diabetes have 1.7-fold higher levels of Galpha(i2) and twofold higher levels of Gbeta(1). Diabetes does not affect other atrial G proteins, including Galpha(i3,) Galpha(s), Galpha(o), and Gbeta(2). These data represent the first demonstration of an increase in a G(i)-coupled receptor, Galpha(i2), and Gbeta(1), in atrium of patients with diabetes. These findings suggest a molecular explanation for the increased risk of cardiac disease in patients with diabetes, because increased signaling through G(i) has been shown to lead to the development of dilated cardiomyopathy.

Authors
Richardson, MD; Kilts, JD; Kwatra, MM
MLA Citation
Richardson, MD, Kilts, JD, and Kwatra, MM. "Increased expression of Gi-coupled muscarinic acetylcholine receptor and Gi in atrium of elderly diabetic subjects." Diabetes 53.9 (September 2004): 2392-2396.
PMID
15331550
Source
epmc
Published In
Diabetes
Volume
53
Issue
9
Publish Date
2004
Start Page
2392
End Page
2396
DOI
10.2337/diabetes.53.9.2392

Age increases expression and receptor-mediated activation of G alpha i in human atria.

Recently, we demonstrated that beta2AR and several other Galphas-coupled receptors in human atria also couple to Galphai, a G protein that inhibits adenylyl cyclase (AC). The present study was undertaken to determine whether age increases expression of Galphai in human atrium, and more specifically whether it results in an increase in receptor-mediated activation of Galphai. Right atrial appendages were obtained from 14 mature adult (40-55 years) and 14 elderly (71-79 years) patients undergoing cardiac surgery. Immunoblotting of atrial membranes indicates that elderly atria have 82 +/- 18% more Galphai2 than atria from mature adults (P < 0.002); this increase in Galphai with age is confirmed by pertussis toxin-catalyzed ADP-ribosylation as well as by photoaffinity labeling with [32P]azidoanilido-GTP. We also find that receptor-mediated activation of Galphai is greater in elderly atria and that both basal and receptor-mediated AC activities decrease in elderly atria. These decreases in AC activity can be reversed by disabling Galphai with pertussis toxin, indicating that the age-dependent increases in Galphai expression and activation have functional consequences. Because beta2ARs in human atria mediate contractility through cAMP-mediated phosphorylation of phospholamban, we conclude that an age-induced increase in Galphai may have a role in depressing cardiac function in aged human atria.

Authors
Kilts, JD; Akazawa, T; El-Moalem, HE; Mathew, JP; Newman, MF; Kwatra, MM
MLA Citation
Kilts, JD, Akazawa, T, El-Moalem, HE, Mathew, JP, Newman, MF, and Kwatra, MM. "Age increases expression and receptor-mediated activation of G alpha i in human atria." Journal of Cardiovascular Pharmacology 42.5 (November 2003): 662-670.
PMID
14576516
Source
epmc
Published In
Journal of Cardiovascular Pharmacology
Volume
42
Issue
5
Publish Date
2003
Start Page
662
End Page
670
DOI
10.1097/00005344-200311000-00013

Human substance P receptor lacking the C-terminal domain remains competent to desensitize and internalize.

Substance P receptor (SPR) and its naturally occurring splice-variant, lacking the C-terminal tail, are found in brain and spinal cord. Whether C-terminally truncated SPR desensitizes like full-length SPR is controversial. We used a multivaried approach to determine whether human SPR (hSPR) and a C-terminally truncated mutant, hSPRDelta325, differ in their desensitization and internalization. In HEK-293 cells expressing either hSPRDelta325 or hSPR, SP-induced desensitization of the two receptors was similar when measured by inositol triphosphate accumulation or by transient translocation of coexpressed PKCbetaII-GFP to the plasma membrane. Moreover, translocation of beta-arrestin 1 or 2-GFP (betaarr1-GFP or betaarr2-GFP) to the plasma membrane, and receptor internalization were also similar. However, hSPR and hSPRDelta325 differ in their phosphorylation and in their ability to form beta-arrestin-containing endocytic vesicles. Unlike hSPR, hSPRDelta325 is not phosphorylated to a detectable level in intact HEK293 cells, and whereas hSPR forms vesicles containing either betaarr1-GFP or betaarr2-GFP, hSPRDelta325 does not form any vesicles with betaarr1-GFP, and forms fewer vesicles with betaarr2-GFP. We conclude that truncated hSPR undergoes agonist-dependent desensitization and internalization without detectable receptor phosphorylation.

Authors
Richardson, MD; Balius, AM; Yamaguchi, K; Freilich, ER; Barak, LS; Kwatra, MM
MLA Citation
Richardson, MD, Balius, AM, Yamaguchi, K, Freilich, ER, Barak, LS, and Kwatra, MM. "Human substance P receptor lacking the C-terminal domain remains competent to desensitize and internalize." Journal of Neurochemistry 84.4 (February 2003): 854-863.
PMID
12562528
Source
epmc
Published In
Journal of Neurochemistry
Volume
84
Issue
4
Publish Date
2003
Start Page
854
End Page
863
DOI
10.1046/j.1471-4159.2003.01577.x

Cardiopulmonary bypass decreases G protein-coupled receptor kinase activity and expression in human peripheral blood mononuclear cells.

Cardiopulmonary bypass (CPB) has been implicated in the development of organ injury associated with cardiac surgery. At the molecular level, CPB is accompanied by a pronounced proinflammatory response including an increase in plasma interleukin (IL)-6. The IL-6 has been shown to be increased in rheumatoid arthritis, a chronic inflammatory disease, where it has been implicated in decreasing G protein-coupled receptor kinases (GRKs) in peripheral blood mononuclear cells. Since IL-6 is substantially increased after CPB, the study tested whether the increase of IL-6 during CPB leads to a decrease of GRKs in mononuclear cells. This is important because GRKs regulate the function of G protein-coupled receptors involved in inflammation.Fifteen patients had blood withdrawn before CPB, 2 h after CPB, and on postoperative day one (POD1). Plasma IL-6 concentrations were determined by enzyme-linked immunosorbent assay. The GRK protein expression and activity were determined by Western blot and phosphorylation of rhodopsin using [gamma-(32)P] adenosine triphosphate, respectively.Plasma IL-6 increased over 20-fold after CPB and remained increased on POD1. Cytosolic GRK activity in mononuclear cells decreased by 39 +/- 29%; cytosolic GRK2 and membrane-bound GRK6 decreased by 90 +/- 15 and 65 +/- 43%, respectively. The GRK activity and expression of GRK2/GRK6 on POD1 returned to basal levels in many but not all patients.The CPB causes a profound decrease in mononuclear cell GRKs, and the recovery of these kinases on POD1 is quite variable. The significance of the variable recovery of GRKs after CPB and their potential role as a marker of clinical outcome deserves further investigation.

Authors
Hagen, SA; Kondyra, AL; Grocott, HP; El-Moalem, H; Bainbridge, D; Mathew, JP; Newman, MF; Reves, JG; Schwinn, DA; Kwatra, MM
MLA Citation
Hagen, SA, Kondyra, AL, Grocott, HP, El-Moalem, H, Bainbridge, D, Mathew, JP, Newman, MF, Reves, JG, Schwinn, DA, and Kwatra, MM. "Cardiopulmonary bypass decreases G protein-coupled receptor kinase activity and expression in human peripheral blood mononuclear cells." Anesthesiology 98.2 (February 2003): 343-348.
PMID
12552191
Source
epmc
Published In
Anesthesiology
Volume
98
Issue
2
Publish Date
2003
Start Page
343
End Page
348
DOI
10.1097/00000542-200302000-00012

Age increases cardiac Galpha(i2) expression, resulting in enhanced coupling to G protein-coupled receptors.

Cardiac G protein-coupled receptors that function through stimulatory G protein Galpha(s), such as beta(1)- and beta(2)-adrenergic receptors (beta(1)ARs and beta(2)ARs), play a key role in cardiac contractility. Recent data indicate that several Galpha(s)-coupled receptors in heart also activate Galpha(i), including beta(2)ARs (but not beta(1)ARs). Coupling of cardiac beta(2)ARs to Galpha(i) inhibits adenylyl cyclase and opposes beta(1)AR-mediated apoptosis. Dual coupling of beta(2)AR to both Galpha(s) and Galpha(i) is likely to alter beta(2)AR function in disease, such as congestive heart failure in which Galpha(i) levels are increased. Indeed, heart failure is characterized by reduced responsiveness of betaARs. Cardiac betaAR-responsiveness is also decreased with aging. However, whether age increases cardiac Galpha(i) has been controversial, with some studies reporting an increase and others reporting no change. The present study examines Galpha(i) in left ventricular membranes from young and old Fisher 344 rats by employing a comprehensive battery of biochemical assays. Immunoblotting reveals significant increases with age in left ventricular Galpha(i2), but no changes in Galpha(i3), Galpha(o), Galpha(s), Gbeta(1), or Gbeta(2). Aging also increases ADP-ribosylation of pertussis toxin-sensitive G proteins. Consistent with these results, basal as well as receptor-mediated incorporation of photoaffinity label [(32)P]azidoanilido-GTP indicates higher amounts of Galpha(i2) in older left ventricular membranes. Moreover, both basal and receptor-mediated adenylyl cyclase activities are lower in left ventricular membranes from older rats, and disabling of Galpha(i) with pertussis toxin increases both basal and receptor-stimulated adenylyl cyclase activity. Finally, age produces small but significant increases in muscarinic potency for the inhibition of both beta(1)AR- and beta(2)AR-stimulated adenylyl cyclase activity. The present study establishes that Galpha(i2) increases with age and provides data indicating that this increase dampens adenylyl cyclase activity.

Authors
Kilts, JD; Akazawa, T; Richardson, MD; Kwatra, MM
MLA Citation
Kilts, JD, Akazawa, T, Richardson, MD, and Kwatra, MM. "Age increases cardiac Galpha(i2) expression, resulting in enhanced coupling to G protein-coupled receptors." The Journal of Biological Chemistry 277.34 (August 2002): 31257-31262.
PMID
12065589
Source
epmc
Published In
The Journal of Biological Chemistry
Volume
277
Issue
34
Publish Date
2002
Start Page
31257
End Page
31262
DOI
10.1074/jbc.m203640200

Human substance P receptor undergoes agonist-dependent phosphorylation by G protein-coupled receptor kinase 5 in vitro.

G protein-coupled receptor kinases (GRKs) phosphorylate agonist-occupied G protein-coupled receptors, leading to receptor desensitization. Seven GRKs, designated GRK1 through 7, have been characterized. GRK5 is negatively regulated by protein kinase C. We investigated whether human substance P receptor (hSPR) is a substrate of GRK5. We report that membrane-bound hSPR is phosphorylated by purified GRK5, and that both the rate and extent of phosphorylation increase dramatically in the presence of substance P. The phosphorylation has a high stoichiometry (20+/-4 mol phosphate/mol hSPR) and a low K(m) (1.7+/-0.1 nM). These data provide the first evidence that hSPR is a substrate of GRK5.

Authors
Warabi, K; Richardson, MD; Barry, WT; Yamaguchi, K; Roush, ED; Nishimura, K; Kwatra, MM
MLA Citation
Warabi, K, Richardson, MD, Barry, WT, Yamaguchi, K, Roush, ED, Nishimura, K, and Kwatra, MM. "Human substance P receptor undergoes agonist-dependent phosphorylation by G protein-coupled receptor kinase 5 in vitro." FEBS Lett 521.1-3 (June 19, 2002): 140-144.
PMID
12067742
Source
pubmed
Published In
Febs Letters
Volume
521
Issue
1-3
Publish Date
2002
Start Page
140
End Page
144

Beta(2)-adrenergic and several other G protein-coupled receptors in human atrial membranes activate both G(s) and G(i).

Cardiac G protein-coupled receptors that couple to Galpha(s) and stimulate cAMP formation (eg, beta-adrenergic, histamine, serotonin, and glucagon receptors) play a key role in cardiac inotropy. Recent studies in rodent cardiac myocytes and transfected cells have revealed that one of these receptors, the beta(2)-adrenergic receptor (AR), also couples to the inhibitory G protein Galpha(i) (activation of which inhibits cAMP formation). If beta(2)ARs could be shown to couple to Galpha(i) in the human heart, it would have important ramifications, because levels of Galpha(i) increase with age and in failing human heart. Therefore, we investigated whether beta(2)ARs in the human heart activate Galpha(i). By photoaffinity labeling human atrial membranes with [(32)P]azidoanilido-GTP, followed by immunoprecipitation with antibodies specific for Galpha(i), we found that Galpha(i) is activated by stimulation of beta(2)ARs but not of beta(1)ARs. In addition, we found that other Galpha(s)-coupled receptors also couple to Galpha(i), including histamine, serotonin, and glucagon. When coupling of these receptors to Galpha(i) is disrupted by pertussis toxin, their ability to stimulate adenylyl cyclase is enhanced. These data provide the first evidence that beta(2)AR and many other Galpha(s)-coupled receptors in human atrium also couple to Galpha(i) and that abolishing the coupling of these receptors to Galpha(i) increases the receptor-mediated adenylyl cyclase activity.

Authors
Kilts, JD; Gerhardt, MA; Richardson, MD; Sreeram, G; Mackensen, GB; Grocott, HP; White, WD; Davis, RD; Newman, MF; Reves, JG; Schwinn, DA; Kwatra, MM
MLA Citation
Kilts, JD, Gerhardt, MA, Richardson, MD, Sreeram, G, Mackensen, GB, Grocott, HP, White, WD, Davis, RD, Newman, MF, Reves, JG, Schwinn, DA, and Kwatra, MM. "Beta(2)-adrenergic and several other G protein-coupled receptors in human atrial membranes activate both G(s) and G(i)." Circ Res 87.8 (October 13, 2000): 705-709.
PMID
11029407
Source
pubmed
Published In
Circulation Research
Volume
87
Issue
8
Publish Date
2000
Start Page
705
End Page
709

β2-Adrenergic and several other g protein-coupled receptors in human atrial membranes activate both G(s) and G(i)

Cardiac G protein-coupled receptors that couple to Gα(s) and stimulate cAMP formation (eg, β-adrenergic, histamine, serotonin, and glucagon receptors) play a key role in cardiac inotropy. Recent studies in rodent cardiac myocytes and transfected cells have revealed that one of these receptors, the β 2 -adrenergic receptor (AR), also couples to the inhibitory G protein Gα(i)(activation of which inhibits cAMP formation). If β 2 ARs could be shown to couple to Gα(i) in the human heart, it would have important ramifications, because levels of Gα(i) increase with age and in failing human heart. Therefore, we investigated whether β 2 ARs in the human heart activate Gα(i). By photoaffinity labeling human atrial membranes with [ 32 P]azidoanilido-GTP, followed by immunoprecipitation with antibodies specific for Gα(i), we found that Gα(i) is activated by stimulation of β 2 ARs but not of β 1 ARs. In addition, we found that other Gα(s)-coupled receptors also couple to Gα(i), including histamine, serotonin, and glucagon. When coupling of these receptors to Gα(i) is disrupted by pertussis toxin, their ability to stimulate adenylyl cyclase is enhanced. These data provide the first evidence that β 2 AR and many other Gα(s)-coupled receptors in human atrium also couple to Gα(i) and that abolishing the coupling of these receptors to Gα(i) increases the receptor-mediated adenylyl cyclase activity.

Authors
Kilts, JD; Gerhardt, MA; Richardson, MD; Sreeram, G; Mackensen, GB; Grocott, HP; White, WD; Davis, RD; Newman, MF; Reves, JG; Schwinn, DA; Kwatra, MM
MLA Citation
Kilts, JD, Gerhardt, MA, Richardson, MD, Sreeram, G, Mackensen, GB, Grocott, HP, White, WD, Davis, RD, Newman, MF, Reves, JG, Schwinn, DA, and Kwatra, MM. 2-Adrenergic and several other g protein-coupled receptors in human atrial membranes activate both G(s) and G(i)." Circulation Research 87.8 (October 13, 2000): 705-709.
Source
scopus
Published In
Circulation Research
Volume
87
Issue
8
Publish Date
2000
Start Page
705
End Page
709

β2-Adrenergic and several other g protein-coupled receptors in human atrial membranes activate both G(s) and G(i)

Cardiac G protein-coupled receptors that couple to Gα(s) and stimulate cAMP formation (eg, β-adrenergic, histamine, serotonin, and glucagon receptors) play a key role in cardiac inotropy. Recent studies in rodent cardiac myocytes and transfected cells have revealed that one of these receptors, the β2-adrenergic receptor (AR), also couples to the inhibitory G protein Gα(i)(activation of which inhibits cAMP formation). If β2ARs could be shown to couple to Gα(i) in the human heart, it would have important ramifications, because levels of Gα(i) increase with age and in failing human heart. Therefore, we investigated whether β2ARs in the human heart activate Gα(i). By photoaffinity labeling human atrial membranes with [32P]azidoanilido-GTP, followed by immunoprecipitation with antibodies specific for Gα(i), we found that Gα(i) is activated by stimulation of β2ARs but not of β1ARs. In addition, we found that other Gα(s)-coupled receptors also couple to Gα(i), including histamine, serotonin, and glucagon. When coupling of these receptors to Gα(i) is disrupted by pertussis toxin, their ability to stimulate adenylyl cyclase is enhanced. These data provide the first evidence that β2AR and many other Gα(s)-coupled receptors in human atrium also couple to Gα(i) and that abolishing the coupling of these receptors to Gα(i) increases the receptor-mediated adenylyl cyclase activity.

Authors
Kilts, JD; Gerhardt, MA; Richardson, MD; Sreeram, G; Mackensen, GB; Grocott, HP; White, WD; Davis, RD; Newman, MF; Reves, JG; Schwinn, DA; Kwatra, MM
MLA Citation
Kilts, JD, Gerhardt, MA, Richardson, MD, Sreeram, G, Mackensen, GB, Grocott, HP, White, WD, Davis, RD, Newman, MF, Reves, JG, Schwinn, DA, and Kwatra, MM. 2-Adrenergic and several other g protein-coupled receptors in human atrial membranes activate both G(s) and G(i)." Circulation Research 87.8 (2000): 705-709.
Source
scival
Published In
Circulation Research
Volume
87
Issue
8
Publish Date
2000
Start Page
705
End Page
709

Characterization of differences between rapid agonist-dependent phosphorylation and phorbol ester-mediated phosphorylation of human substance P receptor in intact cells.

Substance P receptor (SPR), which plays a key role in pain transmission, is known to undergo rapid agonist-dependent desensitization and internalization. The present study shows that human SPR undergoes agonist-dependent phosphorylation in intact cells. Immunoprecipitation of SPR from 32Pi-labeled Chinese hamster ovary cells stably expressing human SPR (CHO-hSPR) indicates that substance P (SP) causes a rapid (T1/2 < 1 min), dose-dependent (EC50 = 2 nM), and pronounced (5-fold over basal) phosphorylation of SPR. Because SPR in CHO-hSPR couples to Galphaq, Galphas, and Galphao (), we examined the involvement of various second messenger-activated protein kinases in SPR phosphorylation. Although increases in intracellular cyclic AMP or treatment with the calcium ionophore A23187 do not cause SPR phosphorylation, treatment with the protein kinase C (PKC) activator phorbol 12-myristate 13-acetate (PMA) causes a 2.5-fold increase in SPR phosphorylation with a T1/2 of <1 min. However, PKC inhibitor GF109203X has no effect on SP-dependent SPR phosphorylation. Furthermore, although SP treatment phosphorylates SPR on both serine and threonine residues equally, PMA treatment phosphorylates the receptor predominantly on serine residues. Two-dimensional phosphopeptide mapping data indicate that SP-dependent and PMA-dependent phosphorylations of SPR have some unique differences. Taken together, these data suggest that although activation of PKC by PMA can lead to SPR phosphorylation, PKC does not mediate SP-dependent phosphorylation of SPR. In conclusion, the present study represents the first demonstration and characterization of agonist-dependent and PMA-mediated phosphorylation of SPR in intact cells.

Authors
Roush, ED; Warabi, K; Kwatra, MM
MLA Citation
Roush, ED, Warabi, K, and Kwatra, MM. "Characterization of differences between rapid agonist-dependent phosphorylation and phorbol ester-mediated phosphorylation of human substance P receptor in intact cells." Mol Pharmacol 55.5 (May 1999): 855-862.
PMID
10220564
Source
pubmed
Published In
Molecular Pharmacology
Volume
55
Issue
5
Publish Date
1999
Start Page
855
End Page
862

Real-time visualization of the cellular redistribution of G protein-coupled receptor kinase 2 and beta-arrestin 2 during homologous desensitization of the substance P receptor.

The substance P receptor (SPR) is a G protein-coupled receptor (GPCR) that plays a key role in pain regulation. The SPR desensitizes in the continued presence of agonist, presumably via mechanisms that implicate G protein-coupled receptor kinases (GRKs) and beta-arrestins. The temporal relationship of these proposed biochemical events has never been established for any GPCR other than rhodopsin beyond the resolution provided by biochemical assays. We investigate the real-time activation and desensitization of the human SPR in live HEK293 cells using green fluorescent protein conjugates of protein kinase C, GRK2, and beta-arrestin 2. The translocation of protein kinase C betaII-green fluorescent protein to and from the plasma membrane in response to substance P indicates that the human SPR becomes activated within seconds of agonist exposure, and the response desensitizes within 30 s. This desensitization process coincides with a redistribution of GRK2 from the cytosol to the plasma membrane, followed by a robust redistribution of beta-arrestin 2 and a profound change in cell morphology that occurs after 1 min of SPR stimulation. These data establish a role for GRKs and beta-arrestins in homologous desensitization of the SPR and provide the first visual and temporal resolution of the sequence of events underlying homologous desensitization of a GPCR in living cells.

Authors
Barak, LS; Warabi, K; Feng, X; Caron, MG; Kwatra, MM
MLA Citation
Barak, LS, Warabi, K, Feng, X, Caron, MG, and Kwatra, MM. "Real-time visualization of the cellular redistribution of G protein-coupled receptor kinase 2 and beta-arrestin 2 during homologous desensitization of the substance P receptor." The Journal of Biological Chemistry 274.11 (March 1999): 7565-7569.
PMID
10066824
Source
epmc
Published In
The Journal of Biological Chemistry
Volume
274
Issue
11
Publish Date
1999
Start Page
7565
End Page
7569
DOI
10.1074/jbc.274.11.7565

Acute myocardial beta-adrenergic receptor dysfunction after cardiopulmonary bypass in patients with cardiac valve disease. Duke Heart Center Perioperative Desensitization Group.

BACKGROUND: Patients with cardiac valve disease (CVD) frequently have congestive heart failure (CHF) and chronic myocardial beta-adrenergic receptor (beta AR) desensitization. Cardiac surgery requiring cardiopulmonary bypass (CPB) is associated with increased plasma catecholamine concentrations, which might worsen myocardial beta AR function. We therefore tested the hypothesis that acute beta AR dysfunction occurs during CPB in patients with CVD. METHODS AND RESULTS: After informed consent, 50 patients were enrolled. Right atrial biopsy samples were obtained at initiation and conclusion of CPB to assess beta AR density and adenylyl cyclase (AC) activity. Plasma catecholamine concentrations increased 3-fold during CPB (P < 0.01). Although beta AR density remained constant, isoproterenol-stimulated AC activity decreased significantly (approximately 30%; P < 0.005). AC activity decreased 22% and 24% with direct G protein (NaF) or AC (manganese) activation, respectively. Patients with or without preoperative CHF exhibited similar degrees of acute myocardial beta AR dysfunction during CPB. CONCLUSIONS: Acute myocardial beta AR dysfunction occurs during CPB in patients with severe CVD requiring surgical correction, with or without preexisting CHF. The primary underlying mechanism involves functional uncoupling of the beta AR signal transduction pathway at the level of the AC moiety. This information should facilitate development of agents designed to prevent acute myocardial beta AR dysfunction during CPB, potentially leading to improved outcome in this high-risk population.

Authors
Gerhardt, MA; Booth, JV; Chesnut, LC; Funk, BL; el-Moalem, HE; Kwatra, MM; Schwinn, DA
MLA Citation
Gerhardt, MA, Booth, JV, Chesnut, LC, Funk, BL, el-Moalem, HE, Kwatra, MM, and Schwinn, DA. "Acute myocardial beta-adrenergic receptor dysfunction after cardiopulmonary bypass in patients with cardiac valve disease. Duke Heart Center Perioperative Desensitization Group." Circulation 98.19 Suppl (November 10, 1998): II275-II281.
PMID
9852914
Source
pubmed
Published In
Circulation
Volume
98
Issue
19 Suppl
Publish Date
1998
Start Page
II275
End Page
II281

Acute myocardial beta-adrenergic receptor dysfunction after cardiopulmonary bypass in patients with cardiac valve disease

Authors
Gerhardt, MA; Booth, JV; Chesnut, LC; Funk, BL; El-Moalem, HE; Kwatra, MM; Schwinn, DA
MLA Citation
Gerhardt, MA, Booth, JV, Chesnut, LC, Funk, BL, El-Moalem, HE, Kwatra, MM, and Schwinn, DA. "Acute myocardial beta-adrenergic receptor dysfunction after cardiopulmonary bypass in patients with cardiac valve disease." Circulation 98.19 (November 10, 1998): II275-II281. (Academic Article)
Source
wos
Published In
Circulation
Volume
98
Issue
19
Publish Date
1998
Start Page
II275
End Page
II281

Subtype specific regulation of human vascular alpha(1)-adrenergic receptors by vessel bed and age

Authors
Rudner, XL; Berkowitz, DE; Funk, BL; Kwatra, MM; Schwinn, DA
MLA Citation
Rudner, XL, Berkowitz, DE, Funk, BL, Kwatra, MM, and Schwinn, DA. "Subtype specific regulation of human vascular alpha(1)-adrenergic receptors by vessel bed and age." CIRCULATION 98.17 (October 27, 1998): 540-540.
Source
wos-lite
Published In
Circulation
Volume
98
Issue
17
Publish Date
1998
Start Page
540
End Page
540

Acute depression of myocardial beta-adrenergic receptor signaling during cardiopulmonary bypass: impairment of the adenylyl cyclase moiety. Duke Heart Center Perioperative Desensitization Group.

BACKGROUND: Previously the authors showed that myocardial beta-adrenergic (betaAR) function is reduced after cardiopulmonary bypass (CPB) in a canine model Whether CPB results in similar effects on betaAR function in adult humans is not known. Therefore the current study tested two hypotheses: (1) That myocardial betaAR signaling is reduced in adult humans after CPB, and (2) that administration of long-term preoperative betaAR antagonists prevents this process. METHODS: After they gave informed consent, 52 patients undergoing aortocoronary surgery were enrolled. Atrial biopsies were obtained before CPB and immediately before discontinuation of CPB. Plasma catecholamine concentrations, myocardial betaAR density, and functional responsiveness (basal, isoproterenol, zinterol, sodium fluoride, and manganese-stimulated adenylyl cyclase activity) were assessed. RESULTS: Catecholamine levels increased significantly during CPB (P < 0.005). Myocardial betaAR adenylyl cyclase coupling decreased during CPB, as evidenced by a 21% decrease in isoproterenol-stimulated adenylyl cyclase activity (750 [430] pmol cyclic adenosine monophosphate per milligram total protein 15 min before CPB compared with 540 [390] at the end of CPB, P = 0.0062, medians [interquartile range]) despite constant betaAR density. Differential activation along the betaAR signal transduction cascade localized the defect to the adenylyl cyclase moiety. Administration of long-term preoperative betaAR antagonists did not prevent acute CPB-induced myocardial betaAR dysfunction. CONCLUSIONS: These data indicate that the myocardial adenylyl cyclase response to betaAR agonists decreases acutely in adults during aortocoronary surgery requiring CPB, regardless of whether long-term preoperative betaAR antagonists are administered. The mechanism underlying acute betaAR dysfunction appears to be direct impairment of the adenylyl cyclase moiety. Similar increases in manganese-stimulated activity before and at the end of CPB show preserved adenylyl cyclase catalytic activity, suggesting that other mechanisms (such as decreased protein levels or altered isoform expression or function) may be responsible for decreased adenylyl cyclase function.

Authors
Booth, JV; Landolfo, KP; Chesnut, LC; Bennett-Guerrero, E; Gerhardt, MA; Atwell, DM; El-Moalem, HE; Smith, MS; Funk, BL; Kuhn, CM; Kwatra, MM; Schwinn, DA
MLA Citation
Booth, JV, Landolfo, KP, Chesnut, LC, Bennett-Guerrero, E, Gerhardt, MA, Atwell, DM, El-Moalem, HE, Smith, MS, Funk, BL, Kuhn, CM, Kwatra, MM, and Schwinn, DA. "Acute depression of myocardial beta-adrenergic receptor signaling during cardiopulmonary bypass: impairment of the adenylyl cyclase moiety. Duke Heart Center Perioperative Desensitization Group." Anesthesiology 89.3 (September 1998): 602-611.
PMID
9743395
Source
epmc
Published In
Anesthesiology
Volume
89
Issue
3
Publish Date
1998
Start Page
602
End Page
611
DOI
10.1097/00000542-199809000-00008

beta(2)-adrenergic receptors in human atrial membranes activate both G(s) and G(i).

Authors
Gerhardt, MA; Barnett, TN; Barry, WT; Schwinn, DA; Kwatra, MM
MLA Citation
Gerhardt, MA, Barnett, TN, Barry, WT, Schwinn, DA, and Kwatra, MM. "beta(2)-adrenergic receptors in human atrial membranes activate both G(s) and G(i)." ANESTHESIOLOGY 89.3A (September 1998): U233-U233.
Source
wos-lite
Published In
Anesthesiology
Volume
89
Issue
3A
Publish Date
1998
Start Page
U233
End Page
U233

A large population study reveals reduced anesthetic requirements in females

Authors
DeLong, ER; Kwatra, MM; Gan, TJ; Glass, PSA; Sanderson, IC; Gilbert, WC; Coleman, RL; Lubarsky, DA; Reves, JG
MLA Citation
DeLong, ER, Kwatra, MM, Gan, TJ, Glass, PSA, Sanderson, IC, Gilbert, WC, Coleman, RL, Lubarsky, DA, and Reves, JG. "A large population study reveals reduced anesthetic requirements in females." ANESTHESIOLOGY 89.3A (September 1998): U191-U191.
Source
wos-lite
Published In
Anesthesiology
Volume
89
Issue
3A
Publish Date
1998
Start Page
U191
End Page
U191

Characterization of [H-3]forskolin binding to human atrial membranes

Authors
Wendelburg, BE; Barnett, TN; Kwatra, MM; Schwinn, DA
MLA Citation
Wendelburg, BE, Barnett, TN, Kwatra, MM, and Schwinn, DA. "Characterization of [H-3]forskolin binding to human atrial membranes." ANESTHESIOLOGY 89.3A (September 1998): U464-U464.
Source
wos-lite
Published In
Anesthesiology
Volume
89
Issue
3A
Publish Date
1998
Start Page
U464
End Page
U464

Human substance P receptor expressed in Chinese hamster ovary cells directly activates G(alpha q/11), G(alpha s), G(alpha o).

Substance P receptor (SPR) stably expressed in Chinese hamster ovary (CHO) cells stimulates at least three second messenger systems including phosphoinositide hydrolysis, cyclic AMP (cAMP) formation, and arachidonic acid release. Whether these second messenger systems are activated via single or multiple G proteins is not known. Therefore, in the present study we examined whether human SPR (hSPR) stably expressed in CHO cells activates multiple G proteins. This was achieved by photoaffinity labeling of G(alpha)-subunits with [32P]azidoanilido-GTP ([32P]AA-GTP) upon hSPR stimulation in CHO-hSPR membranes followed by immunoprecipitation of the labeled G(alpha)-subunits with antibodies specific for various G(alpha)-subunits. These experiments reveal that hSPR directly activates G(alpha q/11), G(alpha s) and G(alpha o). While hSPR is known to couple G(alpha q/11), the present study provides the first evidence that hSPR can also activate G(alpha s) and G(alpha o) in a mammalian system.

Authors
Roush, ED; Kwatra, MM
MLA Citation
Roush, ED, and Kwatra, MM. "Human substance P receptor expressed in Chinese hamster ovary cells directly activates G(alpha q/11), G(alpha s), G(alpha o)." FEBS Lett 428.3 (May 29, 1998): 291-294.
PMID
9654151
Source
pubmed
Published In
Febs Letters
Volume
428
Issue
3
Publish Date
1998
Start Page
291
End Page
294

Multiple potential regulatory elements in the 5' flanking region of the human alpha 1a-adrenergic receptor.

In spite of their critical importance in myocardial hypertrophy and benign prostatic hyperplasia, nothing is known about mechanisms underlying transcriptional regulation of alpha 1a-adrenergic receptors (alpha 1aARs). Therefore we cloned 6.2 kb of novel sequence upstream of the initiator ATG in the human alpha 1aAR gene. Sequence analysis reveals a TATA-less promoter, the presence of several initiator (Inr) consensus sequences, multiple GC rich regions consistent with Sp-1 binding, and consensus sequences for AP-1 and AP-2 as well as putative cis transcriptional regulatory elements for binding of CREB (cyclic-AMP response element binding protein), glucocorticoids, estrogen, and insulin. Compared to the alpha 1bAR, the alpha 1aAR has several more cis regulatory elements, suggesting more complex regulation. The importance of alpha 1aARs in human disease makes it imperative to determine mechanisms underlying transcription and ultimately expression of this receptor. These studies can now be undertaken with the availability of human alpha 1aAR 5'-flanking and 5'-untranslated sequence.

Authors
Lee, K; Richardson, CD; Razik, MA; Kwatra, MM; Schwinn, DA
MLA Citation
Lee, K, Richardson, CD, Razik, MA, Kwatra, MM, and Schwinn, DA. "Multiple potential regulatory elements in the 5' flanking region of the human alpha 1a-adrenergic receptor." DNA Seq 8.4 (March 1998): 271-276.
PMID
10520459
Source
pubmed
Published In
DNA Sequence: Journal of DNA Mapping, Sequencing, and Analysis
Volume
8
Issue
4
Publish Date
1998
Start Page
271
End Page
276

Characterization of GRK2-catalyzed phosphorylation of the human substance P receptor in Sf9 membranes.

G protein-coupled receptor kinases (GRKs) phosphorylate agonist-occupied G protein-coupled receptors (GPCRs), resulting in GPCR desensitization. GRK2 is one of the better studied of the six known GRKs and phosphorylates several GPCRs. In a previous study, we documented that GRK2 and GRK3 phosphorylate purified and reconstituted rat substance P receptor (rSPR) [Kwatra et al. (1993) J. Biol. Chem. 268, 9161-9164]. Here, we characterize in detail GRK2-catalyzed phosphorylation of human SPR (hSPR) in intact membranes. GRK2 phosphorylates hSPR in urea-washed Sf9 membranes in an agonist-dependent manner with a stoichiometry of 19 +/- 1 mol of phosphate/mol of receptor, which increases slightly (1.3-fold increase) in the presence of G beta gamma. Kinetic analyses indicate that receptor phosphorylation occurs with a Km of 6.3 +/- 0.4 nM and a Vmax of 1.8 +/- 0.1 nmol/min/mg; these kinetic parameters are only slightly affected by G beta gamma [Km = 3.6 +/- 1.0 nM and Vmax = 2.2 +/- 0.2 nmol/min/mg]. The lack of a strong stimulatory effect of G beta gamma on GRK2-catalyzed phosphorylation of hSPR is surprising since G beta gamma potently stimulates GRK2-catalyzed phosphorylation of beta 2-adrenergic receptor and rhodopsin. Involvement of G beta gamma endogenously present in membranes is ruled out as a source of high levels of hSPR phosphorylation, since receptor phosphorylation was not affected by guanine nucleotides that suppress or enhance the release of endogenous G beta gamma. The present study determines, for the first time, the kinetics of phosphorylation of a receptor substrate of GRK2 in intact membranes. Further, our results identify hSPR as a unique substrate of GRK2 whose phosphorylation is strong even in the absence of G beta gamma.

Authors
Nishimura, K; Warabi, K; Roush, ED; Frederick, J; Schwinn, DA; Kwatra, MM
MLA Citation
Nishimura, K, Warabi, K, Roush, ED, Frederick, J, Schwinn, DA, and Kwatra, MM. "Characterization of GRK2-catalyzed phosphorylation of the human substance P receptor in Sf9 membranes." Biochemistry 37.5 (February 3, 1998): 1192-1198.
PMID
9477943
Source
pubmed
Published In
Biochemistry
Volume
37
Issue
5
Publish Date
1998
Start Page
1192
End Page
1198
DOI
10.1021/bi972302s

New developments in cardiovascular adrenergic receptor pharmacology: molecular mechanisms and clinical relevance.

Authors
Smiley, RM; Kwatra, MM; Schwinn, DA
MLA Citation
Smiley, RM, Kwatra, MM, and Schwinn, DA. "New developments in cardiovascular adrenergic receptor pharmacology: molecular mechanisms and clinical relevance." J Cardiothorac Vasc Anesth 12.1 (February 1998): 80-95. (Review)
PMID
9509364
Source
pubmed
Published In
Journal of Cardiothoracic and Vascular Anesthesia
Volume
12
Issue
1
Publish Date
1998
Start Page
80
End Page
95

Human substance P receptor expressed in Sf9 cells couples with multiple endogenous G proteins.

To identify the G proteins involved in the function of human substance P receptor (hSPR), the receptor was expressed in Sf9 cells using the baculovirus expression system. Maximal hSPR expression was up to 65 pmol/mg membrane protein. The following data indicated that hSPR in Sf9 membranes is coupled to endogenous G proteins: 1) binding of agonist radioligand [125I]BHSP to the receptor was sensitive to guanine nucleotides; and 2) stimulation of the receptor increased [35S]GTPgammaS binding. The hSPR-associated G proteins were identified by photoaffinity labeling with [alpha-32P]-azidoanilido GTP ([alpha-32P]AAGTP), followed by immunoprecipitation of the labeled G proteins with antibodies specific for various Galpha-subunits. These experiments showed that stimulation of hSPR in Sf9 membranes activated multiple endogenous G proteins including Galpha(o), Galpha(q/11), and Galpha(s). While hSPR's ability to associate with Gq/11 is well-documented, the present study provides the first evidence of hSPR's potential to activate Galpha(o) and Galpha(s).

Authors
Nishimura, K; Frederick, J; Kwatra, MM
MLA Citation
Nishimura, K, Frederick, J, and Kwatra, MM. "Human substance P receptor expressed in Sf9 cells couples with multiple endogenous G proteins." J Recept Signal Transduct Res 18.1 (January 1998): 51-65.
PMID
9493567
Source
pubmed
Published In
Journal of Receptor and Signal Transduction Research
Volume
18
Issue
1
Publish Date
1998
Start Page
51
End Page
65
DOI
10.3109/10799899809039164

Expression and regulation of alpha 1-adrenergic receptors in human tissues.

Authors
Schwinn, DA; Kwatra, MM
MLA Citation
Schwinn, DA, and Kwatra, MM. "Expression and regulation of alpha 1-adrenergic receptors in human tissues." Adv Pharmacol 42 (1998): 390-394.
PMID
9327922
Source
pubmed
Published In
Advances in Pharmacology (San Diego, Calif.)
Volume
42
Publish Date
1998
Start Page
390
End Page
394

Acute depression of myocardial β-adrenergic receptor signaling during cardiopulmonary bypass. Impairment of the adenylyl cyclase moiety

Background: Previously the authors showed that myocardial β-adrenergic (βAR) function is reduced after cardiopulmonary bypass (CPB) in a canine model. Whether CPB results in similar effects on βAR function in adult humans is not known. Therefore the current study tested two hypotheses: (1) That myocardial AR signaling is reduced in adult humans after CPB, and (2) that administration of long-term preoperative βAR antagonists prevents this process. Methods: After they gave informed consent, 52 patients undergoing aortocoronary surgery were enrolled. Atrial biopsies were obtained before CPB and immediately before discontinuation of CPB. Plasma catecholamine concentrations, myocardial βAR density, and functional responsiveness (basal, isoproterenol, zinterol, sodium fluoride, and manganese-stimulated adenylyl cyclase activity) were assessed. Results: Catecholamine levels increased significantly during CPB (P < 0.005). Myocardial βAR adenylyl cyclase coupling decreased during CPB, as evidenced by a 21% decrease in isoproterenol-stimulated adenylyl cyclase activity (750 [430] pmol cyclic adenosine monophosphate per milligram total protein 15 min before CPB compared with 540 [390] at the end of CPB, P = 0.0062, medians [interquartile range]) despite constant βAR density. Differential activation along the βAR signal transduction cascade localized the defect to the adenylyl cyclase moiety. Administration of long-term preoperative βAR antagonists did not prevent acute CPB-induced myocardial βAR dysfunction. Conclusions: These data indicate that the myocardial adenylyl cyclase response to βAR agonists decreases acutely in adults during aortocoronary surgery requiring CPB, regardless of whether long-term preoperative βAR antagonists are administered. The mechanism underlying acute βAR dysfunction appears to be direct impairment of the adenylyl cyclase moiety. Similar increases in manganese-stimulated activity before and at the end of CPB show preserved adenylyl cyclase catalytic activity, suggesting that other mechanisms (such as decreased protein levels or altered isoform expression or function may be responsible for decreased adenylyl cyclase function.

Authors
Booth, JV; Landolfo, KP; Chesnut, LC; Bennett-Guerrero, E; Gerhardt, MA; Atwell, DM; El-Moalem, HE; Smith, MS; Funk, BL; Kuhn, CM; Kwatra, MM; Schwinn, DA
MLA Citation
Booth, JV, Landolfo, KP, Chesnut, LC, Bennett-Guerrero, E, Gerhardt, MA, Atwell, DM, El-Moalem, HE, Smith, MS, Funk, BL, Kuhn, CM, Kwatra, MM, and Schwinn, DA. "Acute depression of myocardial β-adrenergic receptor signaling during cardiopulmonary bypass. Impairment of the adenylyl cyclase moiety." Anesthesiology 89.3 (1998): 602-611.
Source
scival
Published In
Anesthesiology
Volume
89
Issue
3
Publish Date
1998
Start Page
602
End Page
611
DOI
10.1097/00000542-199809000-00008

Acute myocardial β-adrenergic receptor dysfunction after cardiopulmonary bypass in patients with cardiac valve disease

Background - Patients with cardiac valve disease (CVD) frequently have congestive heart failure (CHF) and chronic myocardial β-adrenergic receptor (βAR) desensitization. Cardiac surgery requiring cardiopulmonary bypass (CPB) is associated with increased plasma catecholamine concentrations, which might worsen myocardial βAR function. We therefore tested the hypothesis that acute βAR dysfunction occurs during CPB in patients with CVD. Methods and Results - After informed consent, 50 patients were enrolled. Right atrial biopsy samples were obtained at initiation and conclusion of CPB to assess βAR density and adenylyl cyclase (AC) activity. Plasma catecholamine concentrations increased 3-fold during CPB (P<0.01). Although βAR density remained constant, isoproterenol-stimulated AC activity decreased significantly (≃30%; P<0.005). AC activity decreased 22% and 24% with direct G protein (NaF) or AC (manganese) activation, respectively. Patients with or without preoperative CHF exhibited similar degrees of acute myocardial βAR dysfunction during CPB. Conclusions - Acute myocardial βAR dysfunction occurs during CPB in patients with severe CVD requiring surgical correction, with or without preexisting CHF. The primary underlying mechanism involves functional uncoupling of the βAR signal transduction pathway at the level of the AC moiety. This information should facilitate development of agents designed to prevent acute myocardial βAR dysfunction during CPB, potentially leading to improved outcome in this high-risk population.

Authors
Gerhardt, MA; Booth, JV; Chesnut, LC; Funk, BL; El-Moalem, HE; Kwatra, MM; Schwinn, DA
MLA Citation
Gerhardt, MA, Booth, JV, Chesnut, LC, Funk, BL, El-Moalem, HE, Kwatra, MM, and Schwinn, DA. "Acute myocardial β-adrenergic receptor dysfunction after cardiopulmonary bypass in patients with cardiac valve disease." Circulation 98.19 SUPPL. (1998): II275-II281.
Source
scival
Published In
Circulation
Volume
98
Issue
19 SUPPL.
Publish Date
1998
Start Page
II275
End Page
II281

Multiple potential regulatory elements in the 5′ flanking region of the human alalpha;1a,-adrenergic receptor:short communication

In spite of their critical importance in myocardial hypertrophy and benign prostatic hyperplasia, nothing is known about mechanisms underlying transcriptional regulation of αla-adrenergic receptors (αl, ARs). Therefore we cloned 6.2kb of novel sequence upstream of the initiator ATG in the human αlaAR gene. Sequence analysis reveals a TATA-less promoter, the presence of several initiator (Inr) consensus sequences, multiple GC rich regions consistent with Sp-1 binding, and consensus sequences for AP-1 and AP-2 as well as putative cis transcriptional regulatory elements for binding of CREB (cyclic-AMP response element binding protein), glucocorticoids, estrogen, and insulin. Compared to the αlbAR, the αlaAR has several more cis regulatory elements, suggesting more complex regulation. The importance of αlaARs in human disease makes it imperative to determine mechanisms underlying transcription and ultimately expression of this receptor. These studies can now be undertaken with the availability of human αlaAR 5′-flanking and 5′-untranslated sequence. © 1998 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted.

Authors
Lee, K; Richardson, CD; Razik, MA; Kwatra, MM; Schwinn, DA
MLA Citation
Lee, K, Richardson, CD, Razik, MA, Kwatra, MM, and Schwinn, DA. "Multiple potential regulatory elements in the 5′ flanking region of the human alalpha;1a,-adrenergic receptor:short communication." Mitochondrial DNA 8.4 (1998): 271-276.
Source
scival
Published In
Mitochondrial Dna
Volume
8
Issue
4
Publish Date
1998
Start Page
271
End Page
276
DOI
10.3109/10425179809008464

α1,-Adrenoceptor Subtypes in the Human Cardiovascular and Urogenital Systems

Authors
Schwinn, DA; Kwatra, MM
MLA Citation
Schwinn, DA, and Kwatra, MM. "α1,-Adrenoceptor Subtypes in the Human Cardiovascular and Urogenital Systems." Advances in Pharmacology 42.C (December 1, 1997): 390-394.
Source
scopus
Published In
Advances in Pharmacology (San Diego, Calif.)
Volume
42
Issue
C
Publish Date
1997
Start Page
390
End Page
394
DOI
10.1016/S1054-3589(08)60771-1

Transcriptional regulation of the human alpha1a-adrenergic receptor gene. Characterization Of the 5'-regulatory and promoter region.

We recently cloned cDNAs encoding three subtypes of human alpha1-adrenergic receptors (alpha1ARs), alpha1a, alpha1b, and alpha1d (Schwinn, D. A., Johnston, G. L., Page, S. O., Mosley, M. J., Wilson, K. H., Worman, N. P., Campbell, S., Fidock, M. D., Furness, L. M., Parry-Smith, D. J., Peter, B., and Bailey, D. S. (1995) J. Pharmacol. Exp. Ther. 272, 134-142) and demonstrated predominance of alpha1aARs in many human tissues (Price, D. T., Lefkowitz, R. J., Caron, M. G., Berkowitz, D., and Schwinn, D. A. (1994) Mol. Pharmacol. 45, 171-175). Several lines of evidence indicate that alpha1aARs are important in clinical diseases such as myocardial hypertrophy and benign prostatic hyperplasia. Therefore, we initiated studies to understand mechanisms underlying regulation of alpha1aAR gene transcription. A genomic clone containing 6.2 kb of 5'-untranslated region of the human alpha1aAR gene was recently isolated. Ribonuclease protection and primer extension assays indicate that alpha1aAR gene transcription occurs at multiple initiation sites with the major site located 696 base pairs upstream of the ATG, where a classic initiator sequence is located. Transfection of luciferase reporter constructs containing varying amounts of 5'-untranslated region into human SK-N-MC neuroblastoma cells indicate that a region extending 125 base pairs upstream from the main transcription initiation site contains full alpha1aAR promoter activity. Furthermore, distinct activator and suppressor elements lie 2-3 and 3-5 kilobase pairs upstream, respectively. Although the alpha1aAR promoter contains neither TATA or CAAT elements, gel shift mobility assays targeting three GC boxes immediately upstream of the main transcription initiation site confirm binding of Sp1. Activity of the alpha1aAR promoter is cell-specific, demonstrating highest activity in cells endogenously expressing alpha1aARs. The human alpha1aAR gene also contains several cis regulatory elements, including several insulin and cAMP response elements. Consistent with these observations, we provide the first evidence that treatment of SK-N-MC cells with insulin and cAMP elevating agents leads to an increase in alpha1aAR expression. In conclusion, these data represent the first characterization of the alpha1aAR gene; our findings should facilitate further studies designed to understand mechanisms regulating alpha1AR subtype-specific expression in healthy and diseased human tissue.

Authors
Razik, MA; Lee, K; Price, RR; Williams, MR; Ongjoco, RR; Dole, MK; Rudner, XL; Kwatra, MM; Schwinn, DA
MLA Citation
Razik, MA, Lee, K, Price, RR, Williams, MR, Ongjoco, RR, Dole, MK, Rudner, XL, Kwatra, MM, and Schwinn, DA. "Transcriptional regulation of the human alpha1a-adrenergic receptor gene. Characterization Of the 5'-regulatory and promoter region." J Biol Chem 272.45 (November 7, 1997): 28237-28246.
PMID
9353275
Source
pubmed
Published In
The Journal of Biological Chemistry
Volume
272
Issue
45
Publish Date
1997
Start Page
28237
End Page
28246

Acute myocardial beta-adrenergic receptor desensitization during cardiopulmonary bypass for cardiac valve surgery

Authors
Schwinn, DA; Gerhardt, MA; Chesnut, LC; Funk, BL; Landolfo, KP; Kwatra, MM
MLA Citation
Schwinn, DA, Gerhardt, MA, Chesnut, LC, Funk, BL, Landolfo, KP, and Kwatra, MM. "Acute myocardial beta-adrenergic receptor desensitization during cardiopulmonary bypass for cardiac valve surgery." CIRCULATION 96.8 (October 21, 1997): 2844-2844.
Source
wos-lite
Published In
Circulation
Volume
96
Issue
8
Publish Date
1997
Start Page
2844
End Page
2844

α1,-Adrenoceptor Subtypes in the Human Cardiovascular and Urogenital Systems

Authors
Schwinn, DA; Kwatra, MM
MLA Citation
Schwinn, DA, and Kwatra, MM. 1,-Adrenoceptor Subtypes in the Human Cardiovascular and Urogenital Systems." Advances in Pharmacology 42.C (1997): 390-394.
Source
scival
Published In
Advances in Pharmacology (San Diego, Calif.)
Volume
42
Issue
C
Publish Date
1997
Start Page
390
End Page
394
DOI
10.1016/S1054-3589(08)60771-1

Membrane-bound human substance p receptor undergoes agonist-dependent phosphorylation by g protein receptor kinase 2 (grk2) to a high stoichiometry and activates grk2 in the absence of gβγ

We expressed the human substance P receptor (hSPR) in Sf9 cells at high levels (>50 pmol/mg membrane protein) and examined its ability to serve as GRK2 substrate in intact membranes. The hSPR in Sf9 membranes was phosphorylated by purified GRK2 in agonist-dependent manner with a stoichiometry of 19 ±1 mol of phosphate / mol receptor (SEM; n =3). Kinetic analysis indicated that GRK2-catalyzed phosphorylation of agonist-occupied hSPR occurs with a Km of 6.3 ±0.4 nM (SEM; n =3 ) and a Vm" of 1.8 ±0.1 nmol/min/ug. These kinetic parameters were marginally affected by Gpr This was surprising because GpY potently activates GRK2-catalyzed phosphorylation of agonistoccupied rhodopsin and β,-adrenergic receptor (β2AR). To determine whether GRK2 was being activated by GPT endogenously present in Sf9 membranes, the phosphorylation experiments were performed in the presence of guanine nucleotides that suppress (GDPβS) or enhance (GTPyS) the release of Gfr These experiments showed that the effects of GDPβS and GTPyS on GRK2-catalyzed phosphorylation of agonistoccupied hSPR were marginal. In conclusion, our data provide two significant findings: 1) agonist-occupied hSPR in Sf9 membranes is an excellent substrate of GRK2; and 2) hSPR, unlike rhodopsin and β,AR, can almost fully activate GRK2 without G βγ.

Authors
Kwatra, MM; Nishimura, K; Warabi, K; Roush, ED; Schwinn, DA
MLA Citation
Kwatra, MM, Nishimura, K, Warabi, K, Roush, ED, and Schwinn, DA. "Membrane-bound human substance p receptor undergoes agonist-dependent phosphorylation by g protein receptor kinase 2 (grk2) to a high stoichiometry and activates grk2 in the absence of gβγ." FASEB Journal 11.9 (1997): A1056-.
Source
scival
Published In
Faseb Journal
Volume
11
Issue
9
Publish Date
1997
Start Page
A1056

Human G(alpha q): cDNA and tissue distribution.

G(alpha q), a member of the Gq family of heterotrimeric G proteins, transduces signals from several G protein-coupled receptors that stimulate membrane phosphoinositide hydrolysis. In order to further define the role of G(alpha q) in the function of G protein-coupled receptors, we have cloned the cDNA encoding human G(alpha q) from a prostate cDNA library. Human G(alpha q) exhibits high homology with its mouse homolog - 94% similarity at the nucleotide level, and 99% similarity at the amino acid level. Northern hybridization data indicate high expression of G(alpha q) mRNA in organs of the human reproductive system including ovary, prostate, and testis.

Authors
Chen, B; Leverette, RD; Schwinn, DA; Kwatra, MM
MLA Citation
Chen, B, Leverette, RD, Schwinn, DA, and Kwatra, MM. "Human G(alpha q): cDNA and tissue distribution." Biochim Biophys Acta 1281.2 (June 11, 1996): 125-128.
PMID
8664309
Source
pubmed
Published In
Biochimica Et Biophysica Acta
Volume
1281
Issue
2
Publish Date
1996
Start Page
125
End Page
128

Immunoaffinity purification of epitope-tagged human beta 2-adrenergic receptor to homogeneity.

To obtain large quantities of pure human beta 2-adrenergic receptor (beta 2-AR) needed for structural studies, an efficient method for beta 2-AR purification was developed using a recombinant receptor with an eight amino acid epitope at its C-terminus. This epitope is recognized by KT3-monoclonal antibody. The epitope tagged beta 2-AR was expressed in Sf9 cells with a specific activity of 5-20 pmol/mg of membrane protein. The epitope-tagged and wild-type receptors had identical ligand binding properties. The tagged receptor was solubilized using dodecyl-beta-maltoside with a quantitative yield. Solubilized epitope-tagged receptors were partially purified by KT3-mAb immunoaffinity in 60-70% yield. Further purification of the receptors on an alprenolol-affinity column resulted in a homogenous preparation with an overall yield of > 30%. The purified receptor was concentrated to > 1 mg/ml without loss of ligand binding activity.

Authors
Kwatra, MM; Schreurs, J; Schwinn, DA; Innis, MA; Caron, MG; Lefkowitz, RJ
MLA Citation
Kwatra, MM, Schreurs, J, Schwinn, DA, Innis, MA, Caron, MG, and Lefkowitz, RJ. "Immunoaffinity purification of epitope-tagged human beta 2-adrenergic receptor to homogeneity." Protein Expr Purif 6.6 (December 1995): 717-721.
PMID
8746622
Source
pubmed
Published In
Protein Expression and Purification
Volume
6
Issue
6
Publish Date
1995
Start Page
717
End Page
721
DOI
10.1006/prep.1995.0001

Cardiac muscarinic potassium channel activity is attenuated by inhibitors of G beta gamma.

The cardiac muscarinic potassium channel (IK.ACh) is activated by a G protein upon receptor stimulation with acetylcholine. The G protein subunit responsible for activation (G alpha versus G beta gamma) has been disputed. We used G beta gamma inhibitors derived from the beta-adrenergic kinase 1 (beta ARK1) to assess the relative importance of G beta gamma in IK.ACh activation. In rabbit atrial myocytes, IK.ACh had a conductance of 49 +/- 6.2 pS. In inside-out patches, the mean open time was 1.60 +/- 0.57 ms, mean time constant (tau o) was 1.59 +/- 0.53 ms, and mean closed time was 3.02 +/- 1.35 ms (n = 38). beta ARK1 is a G beta gamma-sensitive enzyme that interacts with G beta gamma through a defined sequence near its carboxyl terminus. A 28-amino-acid peptide derived from the carboxyl terminus of beta ARK1 (peptide G) increased the closed time to 10.04 ms (P < .001) and decreased opening probability (NPo) by 71% (P < .001). Fusion proteins containing the entire carboxyl terminus of beta ARK1, glutathione S-transferase beta ARK1ct and hexahistidine beta ARK1ct, decreased NPo by 67% (P = .03) and 48% (P = .009), respectively. They also both significantly increased the closed time. None of the inhibitors affected mean open time or channel amplitude. A control peptide derived from a neighboring region of beta ARK1 had no significant effect on IK.ACh activity. These results provide further evidence for the role of G beta gamma in the activation of IK.ACh.

Authors
Nair, LA; Inglese, J; Stoffel, R; Koch, WJ; Lefkowitz, RJ; Kwatra, MM; Grant, AO
MLA Citation
Nair, LA, Inglese, J, Stoffel, R, Koch, WJ, Lefkowitz, RJ, Kwatra, MM, and Grant, AO. "Cardiac muscarinic potassium channel activity is attenuated by inhibitors of G beta gamma." Circulation Research 76.5 (May 1995): 832-838.
PMID
7729000
Source
epmc
Published In
Circulation Research
Volume
76
Issue
5
Publish Date
1995
Start Page
832
End Page
838
DOI
10.1161/01.res.76.5.832

A highly conserved tyrosine residue in G protein-coupled receptors is required for agonist-mediated beta 2-adrenergic receptor sequestration.

An aromatic residue, tyrosine 326 in the prototypical human beta 2-adrenergic receptor, exists in a highly conserved sequence motif in virtually all members of the G protein-coupled receptor family. The potential role of this conserved aromatic amino acid residue in the cellular processes of sequestration (a rapid internalization of the surface receptor) and down-regulation (a slower loss of total cellular receptors) associated with agonist-mediated desensitization of the beta 2-adrenergic receptor was assessed by replacing tyrosine residue 326 with an alanine residue (beta 2AR-Y326A). This mutation completely abolishes agonist-mediated receptor sequestration without affecting the ability of the receptor to activate maximally adenylyl cyclase, to undergo rapid desensitization, and to down-regulate in response to agonist. The only other major change associated with the mutated receptor is a complete loss of the ability to resensitize following rapid desensitization. These results imply that this tyrosine residue, which is part of a highly conserved sequence motif in G protein-coupled receptors, may be responsible for their agonist-mediated sequestration and that sequestration and down-regulation of the receptor are dissociable phenomena. The lack of resensitization in the sequestration-defective beta 2-adrenergic receptor mutant strongly suggests that the sequestration pathway is an important mechanism by which cells re-establish the normal responsiveness of G protein-coupled receptors following the removal of agonist.

Authors
Barak, LS; Tiberi, M; Freedman, NJ; Kwatra, MM; Lefkowitz, RJ; Caron, MG
MLA Citation
Barak, LS, Tiberi, M, Freedman, NJ, Kwatra, MM, Lefkowitz, RJ, and Caron, MG. "A highly conserved tyrosine residue in G protein-coupled receptors is required for agonist-mediated beta 2-adrenergic receptor sequestration." J Biol Chem 269.4 (January 28, 1994): 2790-2795.
PMID
7507928
Source
pubmed
Published In
The Journal of Biological Chemistry
Volume
269
Issue
4
Publish Date
1994
Start Page
2790
End Page
2795

Partially Purified and Reconstituted G-Protein Coupled Receptors as Substrates of Specific Receptor Kinases

Most members of the G-protein-coupled receptor (GPCR) superfamily, which includes several hundred receptors, exhibit agonist-induced desensitization. Studies with rhodopsin and β2-adrenergic receptors indicate that a key biochemical event underlying the process of receptor desensitization is the stimulus-dependent phosphorylation of the receptor catalyzed by a family of specific receptor kinases (GRKs). That this paradigm of receptor desensitization may also apply to other GPCRs is indicated by recent findings that M2-muscarinic acetylcholine, α2-adrenergic, and substance P receptors also undergo stimulus-dependent phosphorylation by GRKs. Whether other GPCRs are regulated by GRKs remains to be evaluated. However, progress toward this goal has been slow, as demonstration of receptor phosphorylation has required substantially purified receptors and methods for purifying most GPCRs do not exist. To circumvent this problem, we have developed a general method for the partial purification and reconstitution of GPCRs expressed in Sf9 cells and find that these receptor preparations are suitable as substrates of various GRKs. Using this approach, we describe the agonist-dependent phosphorylation of human β2-AR and rat substance P receptors by GRKs. Furthermore, we show that partially purified and reconstituted GPCRs are also suitable for studying receptor/G-protein interactions. © 1994 Academic Press. All rights reserved.

Authors
Kwatra, MM; Lefkowitz, RJ; Caron, MG
MLA Citation
Kwatra, MM, Lefkowitz, RJ, and Caron, MG. "Partially Purified and Reconstituted G-Protein Coupled Receptors as Substrates of Specific Receptor Kinases." Methods 6.1 (1994): 11-17.
Source
scival
Published In
Methods (San Diego, Calif.)
Volume
6
Issue
1
Publish Date
1994
Start Page
11
End Page
17
DOI
10.1006/meth.1994.1003

Erratum: Functional consequences of A1 adenosine-receptor phosphorylation by the β-adrenergic receptor kinase (Biochimica et Biophysica Acta - Molecular Cell Research (1993) 1179 (89-97))

Authors
Ramkumar, V; Kwatra, M; Benovic, JL; Stiles, GL
MLA Citation
Ramkumar, V, Kwatra, M, Benovic, JL, and Stiles, GL. "Erratum: Functional consequences of A1 adenosine-receptor phosphorylation by the β-adrenergic receptor kinase (Biochimica et Biophysica Acta - Molecular Cell Research (1993) 1179 (89-97))." Biochimica et Biophysica Acta - Molecular Cell Research 1220.2 (1994): 229--.
Source
scival
Published In
Biochimica et Biophysica Acta - Molecular Cell Research
Volume
1220
Issue
2
Publish Date
1994
Start Page
229-
DOI
10.1016/0167-4889(94)90142-2

Functional consequences of A1 adenosine-receptor phosphorylation by the beta-adrenergic receptor kinase.

Treatment of smooth-muscle cells with R-phenylisopropyladenosine (R-PIA) leads to a loss of A1 adenosine receptor (A1AR)-mediated inhibition of adenylate cyclase, a decrease in receptor number and an increase in receptor phosphorylation. In this study, the role of the beta-adrenergic receptor kinase (beta ARK) in the phosphorylation and inactivation of the A1AR was examined. A1ARs were purified from bovine brain and reconstituted into phospholipid vesicles, with or without a 10-fold excess of Gi/Go (a 50:50 mixture). The reconstituted receptor preparations were phosphorylated with beta ARK in the absence (control) or presence (treated) of R-PIA. R-PIA stimulated A1AR phosphorylation by 2-3-fold over control. Phosphorylation of the A1AR was blocked by XAC, and A1AR antagonist, underscoring its agonist dependence. The stoichiometry of phosphorylation obtained was approx. 1.3 mol of phosphate per mol of A1AR. Phosphorylation of the A1AR by beta ARK was enhanced by an additional 42% when G beta gamma (30 nM) was included in the phosphorylation mixture. In order to test the role of phosphorylation on receptor function, the purified A1AR was reconstituted with a mixture of Gi/Go, phosphorylated with beta ARK and used to determine high-affinity [125I]APNEA (A1AR agonist) binding. Agonist binding was reduced by about 50% in the treated preparations compared to control. In contrast, antagonist ([3H]XAC) binding was increased by about 50%. These data are consistent with an uncoupling of the A1AR from G proteins following receptor phosphorylation. In control preparations, R-PIA stimulated GTPase activity from 0.08 to 0.164 pmol Pi released/pmol Gi/Go per min. Phosphorylation of receptor by beta ARK reduced R-PIA-stimulated GTPase activity by 35%. In addition, phosphorylation of the A1AR by beta ARK decreased R-PIA-stimulated GTP gamma S binding by 62%. These data provide evidence that A1AR phosphorylation by beta ARK results in a diminished receptor-G-protein interaction.

Authors
Ramkumar, V; Kwatra, M; Benovic, JL; Stiles, GL; Stilesa, GL
MLA Citation
Ramkumar, V, Kwatra, M, Benovic, JL, Stiles, GL, and Stilesa, GL. "Functional consequences of A1 adenosine-receptor phosphorylation by the beta-adrenergic receptor kinase." Biochim Biophys Acta 1179.1 (October 7, 1993): 89-97.
PMID
8399355
Source
pubmed
Published In
Biochimica Et Biophysica Acta
Volume
1179
Issue
1
Publish Date
1993
Start Page
89
End Page
97

The substance P receptor, which couples to Gq/11, is a substrate of beta-adrenergic receptor kinase 1 and 2.

The agonist-occupied forms of several G-protein-coupled receptors that modulate the activity of adenylycyclase via Gs (e.g. beta 2-adrenergic) or Gi (e.g. alpha 2-adrenergic and cardiac muscarinic) are phosphorylated by beta-adrenergic receptor kinases (beta ARK 1 and beta ARK 2). beta ARK-catalyzed phosphorylation of these receptors appears to correlate with their agonist-induced desensitization. The possibility that beta ARK isozymes may also be involved in the desensitization of other G-protein-coupled receptors such as those mediating phosphoinositide (PI) hydrolysis was tested by determining the phosphorylation of the substance P receptor (SPR), which is coupled to PI hydrolysis in numerous tissues. Rat SPR was expressed in Sf9 cells, partially purified, and reconstituted in phospholipid vesicles. The reconstituted SPR bound the SPR agonist substance P, 125I-labeled with Bolton-Hunter reagent, with low affinity. However, addition of purified Gq/11 to the reconstituted SPR resulted in the conversion of all the receptors to a high affinity state, suggesting that SPR couples to Gq/11. Phosphorylation of the reconstituted SPR with purified beta ARK 1 or 2 in the absence and presence of substance P (SP) was then studied. In the presence of 100 microM SP, both kinases promoted phosphorylation of the receptor to a stoichiometry of 9 +/- 2 mol of phosphate/mol of receptor. However, no phosphorylation of the receptor could be detected in the absence of agonist. Agonist-induced phosphorylation of the receptor was blocked by coincubation with the SPR antagonist spantide. These results show that beta ARK isozymes may regulate the function of both adenylylcyclase as well as PI-coupled receptors, and suggest a role for beta ARK isozymes in SPR signal transduction.

Authors
Kwatra, MM; Schwinn, DA; Schreurs, J; Blank, JL; Kim, CM; Benovic, JL; Krause, JE; Caron, MG; Lefkowitz, RJ
MLA Citation
Kwatra, MM, Schwinn, DA, Schreurs, J, Blank, JL, Kim, CM, Benovic, JL, Krause, JE, Caron, MG, and Lefkowitz, RJ. "The substance P receptor, which couples to Gq/11, is a substrate of beta-adrenergic receptor kinase 1 and 2." The Journal of Biological Chemistry 268.13 (May 1993): 9161-9164.
PMID
7683643
Source
epmc
Published In
The Journal of Biological Chemistry
Volume
268
Issue
13
Publish Date
1993
Start Page
9161
End Page
9164

Beta-arrestin2, a novel member of the arrestin/beta-arrestin gene family.

Homologous or agonist-specific desensitization of beta 2-adrenergic receptors (beta 2AR) is mediated by the beta-adrenergic receptor kinase (beta ARK) which specifically phosphorylates the agonist-occupied form of the receptor. However, the capacity of beta ARK-phosphorylated beta 2AR to stimulate Gs in a reconstituted system is only minimally impaired. Recently, a protein termed beta-arrestin, was cloned from a bovine brain cDNA library and found to quench phosphorylated beta 2AR-coupling to Gs. Utilizing a low stringency hybridization technique to screen a rat brain cDNA library, we have now isolated cDNA clones representing two distinct beta-arrestin-like genes. One of the cDNAs is the rat homolog of bovine beta-arrestin (beta-arrestin1). In addition, we have isolated a cDNA clone encoding a novel, beta-arrestin-related protein which we have termed beta-arrestin2. Overall, beta-arrestin2 exhibits 78% amino acid identity with beta-arrestin1. The primary structure of these proteins delineates a family of proteins that regulates receptor coupling to G proteins. The capacity of purified beta-arrestin1, beta-arrestin2, and arrestin to inhibit the coupling of phosphorylated receptors to their respective G proteins were assessed in a reconstituted beta 2AR-Gs system and in a reconstituted rhodopsin-GT system. beta-Arrestin2 was equipotent to beta-arrestin1 and specifically inhibited beta 2AR function. Conversely, arrestin inhibited rhodopsin coupling to GT, whereas beta-arrestin1 and beta-arrestin2 were at least 20-fold less potent in this system. beta-Arrestin1 and beta-arrestin2 are predominantly localized in neuronal tissues and in the spleen. However, low mRNA levels can be detected in most peripheral tissues. In the central nervous system, beta-arrestin2 appears to be even more abundant than beta-arrestin1. Immunohistochemical analysis of the tissue distribution of beta-arrestin1 and beta-arrestin2 in rat brain shows extensive, but heterogenous, neuronal labeling of the two proteins. They are found in several neuronal pathways suggesting that they have relatively broad receptor specificity regulating many G protein-coupled receptors. Furthermore, immunoelectron microscopy shows that the beta-arrestins are appropriately situated at postsynaptic sites to act in concert with beta ARK to regulate G protein-coupled neurotransmitter receptors.

Authors
Attramadal, H; Arriza, JL; Aoki, C; Dawson, TM; Codina, J; Kwatra, MM; Snyder, SH; Caron, MG; Lefkowitz, RJ
MLA Citation
Attramadal, H, Arriza, JL, Aoki, C, Dawson, TM, Codina, J, Kwatra, MM, Snyder, SH, Caron, MG, and Lefkowitz, RJ. "Beta-arrestin2, a novel member of the arrestin/beta-arrestin gene family." The Journal of Biological Chemistry 267.25 (September 1992): 17882-17890.
PMID
1517224
Source
epmc
Published In
The Journal of Biological Chemistry
Volume
267
Issue
25
Publish Date
1992
Start Page
17882
End Page
17890

Role of beta gamma subunits of G proteins in targeting the beta-adrenergic receptor kinase to membrane-bound receptors.

The rate and extent of the agonist-dependent phosphorylation of beta 2-adrenergic receptors and rhodopsin by beta-adrenergic receptor kinase (beta ARK) are markedly enhanced on addition of G protein beta gamma subunits. With a model peptide substrate it was demonstrated that direct activation of the kinase could not account for this effect. G protein beta gamma subunits were shown to interact directly with the COOH-terminal region of beta ARK, and formation of this beta ARK-beta gamma complex resulted in receptor-facilitated membrane localization of the enzyme. The beta gamma subunits of transducin were less effective at both enhancing the rate of receptor phosphorylation and binding to the COOH-terminus of beta ARK, suggesting that the enzyme preferentially binds specific beta gamma complexes. The beta gamma-mediated membrane localization of beta ARK serves to intimately link receptor activation to beta ARK-mediated desensitization.

Authors
Pitcher, JA; Inglese, J; Higgins, JB; Arriza, JL; Casey, PJ; Kim, C; Benovic, JL; Kwatra, MM; Caron, MG; Lefkowitz, RJ
MLA Citation
Pitcher, JA, Inglese, J, Higgins, JB, Arriza, JL, Casey, PJ, Kim, C, Benovic, JL, Kwatra, MM, Caron, MG, and Lefkowitz, RJ. "Role of beta gamma subunits of G proteins in targeting the beta-adrenergic receptor kinase to membrane-bound receptors." Science (New York, N.Y.) 257.5074 (August 1992): 1264-1267.
PMID
1325672
Source
epmc
Published In
Science (New York, N.Y.)
Volume
257
Issue
5074
Publish Date
1992
Start Page
1264
End Page
1267
DOI
10.1126/science.1325672

The ligand binding domain of the epidermal growth factor receptor is not required for receptor dimerization.

To examine the role of the ligand binding domain of epidermal growth factor receptor in its dimerization, we studied the dimerization of a truncated form of the receptor that resembles v-erbB in that it lacks a ligand binding domain. Receptor dimerization was determined by sedimentation analysis on sucrose density gradients at different concentrations of Triton X-100. At high concentrations of Triton X-100 (0.2%), the truncated receptor occurred as a monomer and displayed low basal autophosphorylation. By contrast, at low concentrations of Triton X-100 (0.01%), it existed as a dimer and exhibited high basal autophosphorylation. The ability of the truncated receptor to dimerize indicates that the ligand binding domain of the epidermal growth factor receptor is not required for receptor dimerization.

Authors
Kwatra, MM; Bigner, DD; Cohn, JA
MLA Citation
Kwatra, MM, Bigner, DD, and Cohn, JA. "The ligand binding domain of the epidermal growth factor receptor is not required for receptor dimerization." Biochimica Et Biophysica Acta 1134.2 (March 1992): 178-181.
PMID
1554751
Source
epmc
Published In
Biochimica Et Biophysica Acta
Volume
1134
Issue
2
Publish Date
1992
Start Page
178
End Page
181
DOI
10.1016/0167-4889(92)90042-a

β-Arrestin2, a novel member of the arrestin/β-arrestin gene family

Homologous or agonist-specific desensitization of β2-adrenergic receptors (β2AR) is mediated by the β-adrenergic receptor kinase (βARK) which specifically phosphorylates the agonist-occupied form of the receptor. However, the capacity of βARK-phosphorylated β2AR to stimulate G(s) in a reconstituted system is only minimally impaired. Recently, a protein termed β-arrestin, was cloned from a bovine brain cDNA library and found to quench phosphorylated β2AR-coupling to G(s). Utilizing a low stringency hybridization technique to screen a rat brain cDNA library, we have now isolated cDNA clones representing two distinct β-arrestin-like genes. One of the cDNAs is the rat homolog of bovine β-arrestin (β-arrestin1). In addition, we have isolated a cDNA clone encoding a novel, β-arrestin-related protein which we have termed β-arrestin2. Overall, β-arrestin2 exhibits 78% amino acid identity with β-arrestin1. The primary structure of these proteins delineates a family of proteins that regulates receptor coupling to G proteins. The capacity of purified β-arrestin1, β-arrestin2, and arrestin to inhibit the coupling of phosphorylated receptors to their respective G proteins were assessed in a reconstituted β2AR-G(s) system and in a reconstituted rhodopsin-G(T) system. β-Arrestin2 was equipotent to β- arrestin1 and specifically inhibited β2AR function. Conversely, arrestin inhibited rhodopsin coupling to G(T), whereas β-arrestin1 and β-arrestin2 were at least 20-fold less potent in this system. β-Arrestin1 and β- arrestin2 are predominantly localized in neuronal tissues and in the spleen. However, low mRNA levels can be detected in most peripheral tissues. In the central nervous system, β-arrestin2 appears to be even more abundant than β-arrestin1. Immunohistochemical analysis of the tissue distribution of β- arrestin1 and β-arrestin2 in rat brain shows extensive, but heterogenous, neuronal labeling of the two proteins. They are found in several neuronal pathways suggesting that they have relatively broad receptor specificity regulating many G protein-coupled receptors. Furthermore, immunoelectron microscopy shows that the β-arrestins are appropriately situated at postsynaptic sites to act in concert with βARK to regulate G protein-coupled neurotransmitter receptors.

Authors
Attramadal, H; Arriza, JL; Aoki, C; Dawson, TM; Codina, J; Kwatra, MM; Snyder, SH; Caron, MG; Lefkowitz, RJ
MLA Citation
Attramadal, H, Arriza, JL, Aoki, C, Dawson, TM, Codina, J, Kwatra, MM, Snyder, SH, Caron, MG, and Lefkowitz, RJ. "β-Arrestin2, a novel member of the arrestin/β-arrestin gene family." Journal of Biological Chemistry 267.25 (January 1, 1992): 17882-17890.
Source
scopus
Published In
The Journal of Biological Chemistry
Volume
267
Issue
25
Publish Date
1992
Start Page
17882
End Page
17890

Anti-synthetic peptide antibody reacting at the fusion junction of deletion-mutant epidermal growth factor receptors in human glioblastoma.

We have investigated human gliomas that amplify and rearrange the epidermal growth factor receptor gene, with generation of an in-frame deletion mutation of 802 nucleotides in the external domain. This in-frame deletion mutation generates a local amino acid sequence at the fusion junction of what normally were distant polypeptide sequences in the intact epidermal growth factor receptor. This 14-amino acid peptide was chemically synthesized, coupled to keyhole limpet hemocyanin, and used as an immunogen in rabbits. The elicited antibody reacted specifically with the fusion peptide in ELISA. The anti-fusion junction peptide antibody was purified by passage of the antiserum over a peptide affinity column with acidic elution. The purified antibody selectively bound the glioma deletion mutant as compared to the intact epidermal growth factor receptor as assessed by immunocytochemistry, immunofluorescence, immunoprecipitation with gel electrophoresis, and binding experiments using radioiodinated antibody. These data indicate that it is feasible to generate site-specific anti-peptide antibodies that are highly selective for mutant proteins in human tumors. The anti-peptide antibody described here, and other mutation site-specific antibodies, should be ideal candidates for tumor immunoimaging and immunotherapy.

Authors
Humphrey, PA; Wong, AJ; Vogelstein, B; Zalutsky, MR; Fuller, GN; Archer, GE; Friedman, HS; Kwatra, MM; Bigner, SH; Bigner, DD
MLA Citation
Humphrey, PA, Wong, AJ, Vogelstein, B, Zalutsky, MR, Fuller, GN, Archer, GE, Friedman, HS, Kwatra, MM, Bigner, SH, and Bigner, DD. "Anti-synthetic peptide antibody reacting at the fusion junction of deletion-mutant epidermal growth factor receptors in human glioblastoma." Proc Natl Acad Sci U S A 87.11 (June 1990): 4207-4211.
PMID
1693434
Source
pubmed
Published In
Proceedings of the National Academy of Sciences of the United States of America
Volume
87
Issue
11
Publish Date
1990
Start Page
4207
End Page
4211

Regulation of receptor function by protein phosphorylation.

Authors
Hosey, MM; Kwatra, MM; Ptasienski, J; Richardson, RM
MLA Citation
Hosey, MM, Kwatra, MM, Ptasienski, J, and Richardson, RM. "Regulation of receptor function by protein phosphorylation." Ann N Y Acad Sci 588 (1990): 155-163. (Review)
PMID
2192639
Source
pubmed
Published In
Annals of the New York Academy of Sciences
Volume
588
Publish Date
1990
Start Page
155
End Page
163

The porcine heart M2 muscarinic receptor: agonist-induced phosphorylation and comparison of properties with the chick heart receptor.

Recently we showed that the chick heart muscarinic acetylcholine receptor is a phosphoprotein in intact cells and that treatment with agonists results in a striking increase in receptor phosphorylation [J. Biol. Chem. 261:12429-12432 (1986)]. Furthermore, we showed that the agonist-induced increase in the phosphorylation of chick heart muscarinic receptors correlates with receptor desensitization [J. Biol. Chem. 262:16314-16321 (1987)]. We have now extended studies of receptor phosphorylation to mammalian cardiac muscarinic receptors, in order to test the concept that phosphorylation is of general importance in the regulation of muscarinic receptor function. We have determined that, in intact porcine atria, M2 muscarinic receptors are phosphoproteins and that treatment with the agonist carbachol markedly increases receptor phosphorylation, to 4-6 mol of phosphate/mol of protein. Phosphorylation occurs on serine and threonine residues. Activation of either protein kinase C or cAMP-dependent protein kinase did not mimic the effect of agonists on receptor phosphorylation. These results are very similar to those seen with the chick heart muscarinic receptors. To determine whether the porcine and the chick cardiac muscarinic receptors represent similar or different proteins, we undertook detailed pharmacological studies and, in addition, prepared peptide maps of purified muscarinic receptors from chick heart and porcine atria. Our data show that there are marked differences in the pharmacological properties of the chick and the porcine cardiac muscarinic receptors. The peptide maps of the porcine and chick heart muscarinic receptors are also different, suggesting that muscarinic receptors in chick and porcine cardiac cells differ in their primary structure. Taken together, the data show that porcine and chick cardiac muscarinic receptors possess pharmacological and structural differences, but both receptors undergo agonist-mediated phosphorylation in intact cardiac cells. These data support the possibility that receptor phosphorylation may be of general importance in the regulation of muscarinic receptors.

Authors
Kwatra, MM; Ptasienski, J; Hosey, MM
MLA Citation
Kwatra, MM, Ptasienski, J, and Hosey, MM. "The porcine heart M2 muscarinic receptor: agonist-induced phosphorylation and comparison of properties with the chick heart receptor." Mol Pharmacol 35.5 (May 1989): 553-558.
PMID
2725467
Source
pubmed
Published In
Molecular Pharmacology
Volume
35
Issue
5
Publish Date
1989
Start Page
553
End Page
558

Phosphorylation of chick heart muscarinic cholinergic receptors by the beta-adrenergic receptor kinase.

Previous studies have demonstrated that muscarinic cholinergic receptors (mAChR) become markedly phosphorylated when intact cardiac cells are stimulated with a muscarinic agonist. This process appears to be related to the process of receptor desensitization. However, the mechanism of agonist-induced phosphorylation of mAChR is not known. In situ phosphorylation studies suggested that agonist-induced phosphorylation of mAChR may involve the participation of a receptor-specific kinase and/or require agonist occupancy. These observations regarding phosphorylation and desensitization of mAChR are similar to observations made for beta-adrenergic receptors. Recent studies have indicated that homologous desensitization of beta-adrenergic receptors may be due to the phosphorylation of these receptors by a novel protein kinase that only recognizes the agonist-occupied form of the receptors. As muscarinic receptors are structurally homologous to beta-adrenergic receptors, we have initiated studies to identify the protein kinase responsible for the phosphorylation of muscarinic receptors by determining whether the chick heart muscarinic receptor would serve as a substrate for the beta-adrenergic receptor kinase (beta-AR kinase). We report that the purified and reconstituted chick heart muscarinic receptor serves as an excellent substrate in vitro for the beta-AR kinase. Phosphorylation of mAChR receptors by the beta-AR kinase was only observed in the presence of a muscarinic receptor agonist and was prevented in the presence of antagonist. Both the extent of phosphorylation (3-4 mol of P/mol of receptor) and the phosphoamino acid composition of the mAChR after incubation in vitro with beta-AR kinase were similar to the characteristics of agonist-induced phosphorylation of mAChR in situ.(ABSTRACT TRUNCATED AT 250 WORDS)

Authors
Kwatra, MM; Benovic, JL; Caron, MG; Lefkowitz, RJ; Hosey, MM
MLA Citation
Kwatra, MM, Benovic, JL, Caron, MG, Lefkowitz, RJ, and Hosey, MM. "Phosphorylation of chick heart muscarinic cholinergic receptors by the beta-adrenergic receptor kinase." Biochemistry 28.11 (May 1989): 4543-4547.
PMID
2765501
Source
epmc
Published In
Biochemistry
Volume
28
Issue
11
Publish Date
1989
Start Page
4543
End Page
4547
DOI
10.1021/bi00437a005

AGONIST-INDUCED PHOSPHORYLATION OF THE PIG-ATRIAL MUSCARINIC RECEPTOR AND ITS COMPARISON WITH THE CHICK HEART RECEPTOR

Authors
KWATRA, MM; PTASIENSKI, J; HOSEY, MM
MLA Citation
KWATRA, MM, PTASIENSKI, J, and HOSEY, MM. "AGONIST-INDUCED PHOSPHORYLATION OF THE PIG-ATRIAL MUSCARINIC RECEPTOR AND ITS COMPARISON WITH THE CHICK HEART RECEPTOR." FASEB JOURNAL 2.4 (March 15, 1988): A624-A624.
Source
wos-lite
Published In
Faseb Journal
Volume
2
Issue
4
Publish Date
1988
Start Page
A624
End Page
A624

Characterization of cardiac A1 adenosine receptors by ligand binding and photoaffinity labeling.

[125I]N6-(p-aminobenzyl)adenosine and [125I]N6-(p-azidobenzyl)adenosine, which are potent agonists at A1 (Ri) adenosine receptors, have been used to characterize the adenosine receptor in membranes prepared from newborn chick heart. Scatchard analyses of [125I]N6-(p-aminobenzyl)adenosine binding to cardiac membranes revealed that the ligand bound to two affinity states of the receptor with Kd values of 0.7 and 9.9 nM. The corresponding maximum binding (Bmax) values were 25 and 86 fmol/mg of protein, respectively. In the presence of 0.1 mM 5'-guanylyl imidodiphosphate, a single affinity state was detected with a Kd of 9.4 nM and a Bmax of 96 fmol/mg of protein. Direct and indirect ligand binding studies with several adenosine receptor agonists and antagonists were used to compare the characteristics of the cardiac receptor with those of the A1 receptor in the cerebellum. The binding properties of the receptors in the two tissues were very similar although marked differences were observed in the binding kinetics of [125I]N6-(p-azidobenzyl)adenosine. Photo-affinity labeling experiments followed by sodium dodecyl sulfate-gel electrophoresis showed that the cardiac receptor had a apparent molecular weight of 37,600, which was slightly but significantly higher than that of the cerebellar receptor (35,500). The present results show that the cardiac receptor has ligand binding properties and a minimal subunit molecular weight similar to the more thoroughly studied A1 receptor in neural tissue.

Authors
Leung, E; Kwatra, MM; Hosey, MM; Green, RD
MLA Citation
Leung, E, Kwatra, MM, Hosey, MM, and Green, RD. "Characterization of cardiac A1 adenosine receptors by ligand binding and photoaffinity labeling." J Pharmacol Exp Ther 244.3 (March 1988): 1150-1156.
PMID
3252029
Source
pubmed
Published In
The Journal of Pharmacology and Experimental Therapeutics
Volume
244
Issue
3
Publish Date
1988
Start Page
1150
End Page
1156

Correlation of agonist-induced phosphorylation of chick heart muscarinic receptors with receptor desensitization.

We have determined whether the process of agonist-mediated phosphorylation of the muscarinic receptor correlates with the process of muscarinic receptor desensitization in chick cardiac tissue. Exposure of ventricular slices to the agonist carbachol under conditions previously shown to lead to large increases in muscarinic receptor phosphorylation (Kwatra, M. M., and Hosey, M. M. (1986) J. Biol. Chem. 261, 12429-12432) resulted in decreased affinity of the muscarinic receptor for agonists. The agonist oxotremorine mimicked and the antagonist atropine prevented the effects of carbachol on receptor phosphorylation and agonist affinity. The time courses and concentration dependences for agonists to induce phosphorylation of the muscarinic receptor and decreases in agonist affinity were similar. Treatment of chick atria with acetylcholine under conditions which led to receptor phosphorylation resulted in decreased sensitivity of these preparations to the negative inotropic effect of carbachol. Taken together, the results support the concept that phosphorylation of cardiac muscarinic receptors may be related to the process of receptor desensitization. The mechanism by which agonists induce receptor phosphorylation was also investigated. The phosphorylated amino acids formed in response to agonists were serine and threonine. The protein kinase C activator phorbol myristate acetate had no effect on receptor phosphorylation or agonist affinity, nor did it prevent the effects of carbachol on either of these parameters. Receptor phosphorylation also was unaffected by the calmodulin antagonists W-7 and W-13, by elevation of cyclic nucleotides, and by agonists which activate other cardiac receptor systems. The results suggest that the phosphorylation of cardiac muscarinic receptors requires agonist occupancy of the receptor and/or may involve the participation of a selective protein kinase.

Authors
Kwatra, MM; Leung, E; Maan, AC; McMahon, KK; Ptasienski, J; Green, RD; Hosey, MM
MLA Citation
Kwatra, MM, Leung, E, Maan, AC, McMahon, KK, Ptasienski, J, Green, RD, and Hosey, MM. "Correlation of agonist-induced phosphorylation of chick heart muscarinic receptors with receptor desensitization." J Biol Chem 262.34 (December 5, 1987): 16314-16321.
PMID
3680252
Source
pubmed
Published In
The Journal of Biological Chemistry
Volume
262
Issue
34
Publish Date
1987
Start Page
16314
End Page
16321

N6-phenyladenosines: pronounced effect of phenyl substituents on affinity for A2 adenosine receptors.

A number of N6-phenyladenosines with various substitutions on the phenyl ring have been synthesized and tested for their affinities toward brain A1 and A2 adenosine receptors. Compounds with meta substituents, such as (m-hydroxy- and m-iodophenyl)adenosine, were found to have high A1 selectivity. Meta substitution caused a selective decrease in the affinity of these compounds for A2 receptors. The results suggest that, in contrast to what is commonly held, certain N6-substituents have pronounced effects on affinity for brain A2 adenosine receptors. Thus, brain A2 receptors may have a well-defined region that recognizes N6-substitutions.

Authors
Kwatra, MM; Leung, E; Hosey, MM; Green, RD
MLA Citation
Kwatra, MM, Leung, E, Hosey, MM, and Green, RD. "N6-phenyladenosines: pronounced effect of phenyl substituents on affinity for A2 adenosine receptors." J Med Chem 30.5 (May 1987): 954-956.
PMID
3572985
Source
pubmed
Published In
Journal of Medicinal Chemistry
Volume
30
Issue
5
Publish Date
1987
Start Page
954
End Page
956

N6-phenyladenosines: Pronounced effect of phenyl substituents on affinity for A2 adenosine receptors

A number of N6-phenyladenosines with various substitutions on the phenyl ring have been synthesized and tested for their affinities toward brain A1 and A2 adenosine receptors. Compounds with meta substituents, such as (m-hydroxy-and m-iodophenyl)adenosine, were found to have high A1 selectivity. Meta substitution caused a selective decrease in the affinity of these compounds for A2 receptors. The results suggest that, in contrast to what is commonly held, certain N6-substituents have pronounced effects on affinity for brain A2 adenosine receptors. Thus, brain A2 receptors may have a well-defined region that recognizes N6-substitutions. © 1987 American Chemical Society.

Authors
Kwatra, MM; Leung, E; Hosey, MM; Green, RD
MLA Citation
Kwatra, MM, Leung, E, Hosey, MM, and Green, RD. "N6-phenyladenosines: Pronounced effect of phenyl substituents on affinity for A2 adenosine receptors." Journal of Medicinal Chemistry 30.5 (1987): 954-956.
Source
scival
Published In
Journal of Medicinal Chemistry
Volume
30
Issue
5
Publish Date
1987
Start Page
954
End Page
956

Phosphorylation of the cardiac muscarinic receptor in intact chick heart and its regulation by a muscarinic agonist.

We have tested the possibility that regulation of cardiac muscarinic receptor function may involve receptor phosphorylation. Chick heart muscarinic receptors were purified from relatively small amounts of tissue to near homogeneity using a three-step chromatographic procedure that utilized the affinity chromatography procedure of Haga and Haga (Haga, K., and Haga, T. (1983) J. Biol. Chem. 258, 13575-13579). The purified preparations contained a single major peptide which migrated on sodium dodecyl sulfate gels with an apparent Mr of 79,000. When receptors were purified from 32P-bathed hearts, a single major phosphopeptide eluted from the affinity column and comigrated on sodium dodecyl sulfate gels with the band of stained receptor. Treatment of hearts with the agonist carbachol led to marked increases (10-12-fold) in the phosphorylation of the receptor. The results show that the muscarinic receptor is a phosphoprotein in cardiac tissue and that treatment with a receptor agonist regulates its phosphorylation in the intact cell.

Authors
Kwatra, MM; Hosey, MM
MLA Citation
Kwatra, MM, and Hosey, MM. "Phosphorylation of the cardiac muscarinic receptor in intact chick heart and its regulation by a muscarinic agonist." J Biol Chem 261.27 (September 25, 1986): 12429-12432.
PMID
3745197
Source
pubmed
Published In
The Journal of Biological Chemistry
Volume
261
Issue
27
Publish Date
1986
Start Page
12429
End Page
12432

PHOSPHORYLATION OF THE CARDIAC MUSCARINIC RECEPTOR IN INTACT CHICK HEART AND ITS REGULATION BY A MUSCARINIC AGONIST

Authors
KWATRA, MM; HOSEY, MM
MLA Citation
KWATRA, MM, and HOSEY, MM. "PHOSPHORYLATION OF THE CARDIAC MUSCARINIC RECEPTOR IN INTACT CHICK HEART AND ITS REGULATION BY A MUSCARINIC AGONIST." JOURNAL OF BIOLOGICAL CHEMISTRY 261.27 (September 25, 1986): 2429-2432.
Source
wos-lite
Published In
The Journal of Biological Chemistry
Volume
261
Issue
27
Publish Date
1986
Start Page
2429
End Page
2432

CHARACTERIZATION OF CARDIAC ADENOSINE RECEPTORS USING N-6-PHENYLADENOSINES AND A NEW RADIOLIGAND, (I-125)-(M-AMINOPHENYL)ADENOSINE

Authors
KWATRA, MM; HOSEY, MM; GREEN, R
MLA Citation
KWATRA, MM, HOSEY, MM, and GREEN, R. "CHARACTERIZATION OF CARDIAC ADENOSINE RECEPTORS USING N-6-PHENYLADENOSINES AND A NEW RADIOLIGAND, (I-125)-(M-AMINOPHENYL)ADENOSINE." FEDERATION PROCEEDINGS 45.4 (March 5, 1986): 800-800.
Source
wos-lite
Published In
Federation Proceedings
Volume
45
Issue
4
Publish Date
1986
Start Page
800
End Page
800

Specific photoaffinity labelling of inhibitory adenosine receptors.

N6(L-phenylisopropyl)adenosine (L-PIA) and N6(3-iodo-4-azido benzyl)-adenosine (IAzBA) inhibit the adenylate cyclase activity in synaptic membranes of chick cerebellum via Ri adenosine receptors. [3H]L-PIA and [125I]AzBA bind to these membranes with Kd values of approximately 1 nM and Bmax values of approximately 1000 fmol/mg protein. Photolysis of [125I]AzBA bound to synaptic membranes results in the specific incorporation of radioactivity into a protein with Mr = 36,000. This photoincorporation is blocked by simultaneous exposure to L-PIA, theophylline, an adenosine receptor antagonist, or Gpp(NH)p, but not by cytosine, suggesting that the 36,000 dalton protein is the Ri adenosine receptor or a subunit of the receptor that contains the adenosine binding site.

Authors
Choca, JI; Kwatra, MM; Hosey, MM; Green, RD
MLA Citation
Choca, JI, Kwatra, MM, Hosey, MM, and Green, RD. "Specific photoaffinity labelling of inhibitory adenosine receptors." Biochem Biophys Res Commun 131.1 (August 30, 1985): 115-121.
PMID
2994642
Source
pubmed
Published In
Biochemical and Biophysical Research Communications
Volume
131
Issue
1
Publish Date
1985
Start Page
115
End Page
121

Substrate-dependent activation energy of the reaction catalyzed by monoamine oxidase.

Authors
Kwatra, MM; Sourkes, TL
MLA Citation
Kwatra, MM, and Sourkes, TL. "Substrate-dependent activation energy of the reaction catalyzed by monoamine oxidase." Arch Biochem Biophys 210.2 (September 1981): 531-536.
PMID
7305342
Source
pubmed
Published In
Archives of Biochemistry and Biophysics
Volume
210
Issue
2
Publish Date
1981
Start Page
531
End Page
536

Monoamine oxidase of rat skeletal muscle: substrate specificity and half-life.

Authors
Kwatra, MM; Sourkes, TL
MLA Citation
Kwatra, MM, and Sourkes, TL. "Monoamine oxidase of rat skeletal muscle: substrate specificity and half-life." Life Sci 27.24 (December 15, 1980): 2327-2331.
PMID
7207021
Source
pubmed
Published In
Life Sciences
Volume
27
Issue
24
Publish Date
1980
Start Page
2327
End Page
2331

Monoamine oxidase A and B activities in liver of riboflavin-deficient rats.

Authors
Kwatra, MM; Sourkes, TL
MLA Citation
Kwatra, MM, and Sourkes, TL. "Monoamine oxidase A and B activities in liver of riboflavin-deficient rats." Biochem Pharmacol 29.19 (October 1, 1980): 2693-2694.
PMID
7426072
Source
pubmed
Published In
Biochemical Pharmacology
Volume
29
Issue
19
Publish Date
1980
Start Page
2693
End Page
2694

Acetylenics. 2. Synthesis and pharmacology of certain N,N-diakyl-3-phenylpropyn-2-amines. Some analogues with tryptamine-like behavioral effects in mice.

A number of N,N-dialkyl-3-phenylpropyn-2-amines 7 have been prepared and tested for their biological action. Certain analogues show tryptamine-like behavior effects in mice. The tryptamine-like activity of these compounds appears to be controlled by their lipophilicity. These compounds show only weak inhibition of rat liver monoamine oxidase. Although these compounds exhibit tryptamine-like action, experiments seem to indicate that there is no interaction with the tryptamine receptors.

Authors
Kwatra, MM; Simon, DZ; Salvador, RL; Cooper, PD
MLA Citation
Kwatra, MM, Simon, DZ, Salvador, RL, and Cooper, PD. "Acetylenics. 2. Synthesis and pharmacology of certain N,N-diakyl-3-phenylpropyn-2-amines. Some analogues with tryptamine-like behavioral effects in mice." J Med Chem 21.3 (March 1978): 253-257.
PMID
627999
Source
pubmed
Published In
Journal of Medicinal Chemistry
Volume
21
Issue
3
Publish Date
1978
Start Page
253
End Page
257
Show More