Document Detail

Studies on inhibition of angiotensin II receptors in rabbit adrenal and aorta.
MedLine Citation:
PMID:  2918473     Owner:  NLM     Status:  MEDLINE    
Angiotensin II (AII) labeled with 125I binds to rabbit adrenal cortical membranes over a concentration range from 0.5 to 20 nM at an apparent single site with a KD of 5 nM. This binding was inhibited in a surmountable fashion with respect to AII by the peptide analogs sarcosine1 (Sar1),Leu8AII and Phe4, Tyr8 AII when added to the incubation media concomitant with AII addition. With a 30-min preincubation, however, the former inhibitor displayed nonsurmountable kinetics whereas the profile of the latter was unaffected. In rabbit aortic strips with the same preincubation time, the Sar1Leu8AII analog was a nonsurmountable antagonist of the contractile effect of AII whereas the inhibition produced by Phe4,Tyr8AII was surmountable by increasing agonist (AII) concentrations. The inhibitory effect of the former was maintained after repeated washing of the tissue whereas that of the latter was readily reversible. Addition of Phe4,Tyr8AII to the bath 5 min before preincubation protected the tissue from the prolonged AII inhibition by Sar1,Leu8AII. These findings indicate different kinetic modes of AII inhibition by these two antagonists. Phe4,Tyr8AII behaves as a reversible, competitive inhibitor of AII binding, whereas Sar1,Leu8AII combines with the AII receptor in a slowly dissociable manner and is therefore not readily displaced by AII.
R G Pendleton; G Gessner; E Horner
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Publication Detail:
Type:  In Vitro; Journal Article    
Journal Detail:
Title:  The Journal of pharmacology and experimental therapeutics     Volume:  248     ISSN:  0022-3565     ISO Abbreviation:  J. Pharmacol. Exp. Ther.     Publication Date:  1989 Feb 
Date Detail:
Created Date:  1989-04-03     Completed Date:  1989-04-03     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0376362     Medline TA:  J Pharmacol Exp Ther     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  637-43     Citation Subset:  IM    
Rorer Central Research, King of Prussia, Pennsylvania.
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MeSH Terms
1-Sarcosine-8-Isoleucine Angiotensin II / pharmacology*
Adrenal Cortex / drug effects*
Angiotensin II / analogs & derivatives*,  antagonists & inhibitors*
Aorta / drug effects*
Dose-Response Relationship, Drug
Receptors, Angiotensin / drug effects*
Reg. No./Substance:
0/Receptors, Angiotensin; 11128-99-7/Angiotensin II; 9088-01-1/1-Sarcosine-8-Isoleucine Angiotensin II

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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