Angiotensin receptor in the heart of Bothrops jararaca snake

Angiotensin receptor in the heart of Bothrops jararaca snake

Author Breno, M. C. Google Scholar
Porto, C. S. Google Scholar
Picarelli, Z. P. Google Scholar
Institution Universidade Federal de São Paulo (UNIFESP)
Inst Butantan
Abstract Angiotensin II interacts with specific cell surface angiotensin AT(1) and AT(2) receptors and, in some vertebrates, with an atypical angiotensin AT receptor. This study was designed to characterize the angiotensin receptor in the heart of Bothrops jararaca snake. A specific and saturable angiotensin II binding site was detected in cardiac membranes and yielded K-d = 7.34 +/- 1.41 nM and B-max = 72.49 +/- 18 fmol/mg protein. Competition-binding studies showed an angiotensin receptor with low affinity to both angiotensin receptor antagonists, losartan (2-n-butyl-4-chloro-5-hydroxymethyl-1-[(2'-(1H-tetrazol-5-yl)biphenyl-4-yl)methyl]imidazole) and PD123319 ((s)-1-(4-[dimethylamino]-3-methylphenyl)methyl-5-(diphenylacetyl)-4,5,6,7-tetrahydro-1H-imidazo[4,5-c]pyridine-6-carboxylate). Studies on the intracellular signaling pathways showed that phospholipase C/inositol phosphate breakdown and adenylylcyclase/cyclic AMP generation were not coupled with this angiotensin receptor. An adenylylcyclase enzyme sensitive to forskolin was detected. the results indicate the presence of an angiotensin receptor in the heart of B. jararaca snake pharmacologically distinct from angiotensin AT(1) and AT(2) receptors. It seems to belong to a new class of angiotensin receptors, like some other atypical angiotensin AT receptors that have already been described. (C) 2001 Elsevier Science B.V. All rights reserved.
Keywords angiotensin receptor
angiotensin AT(1) receptor-selective antagonist
angiotensin AT(2) receptor-selective antagonist
inositol phosphate
adenylylcyclase forskolin-sensitive
heart
Language English
Date 2001-04-06
Published in European Journal of Pharmacology. Amsterdam: Elsevier B.V., v. 417, n. 1-2, p. 27-35, 2001.
ISSN 0014-2999 (Sherpa/Romeo, impact factor)
Publisher Elsevier B.V.
Extent 27-35
Origin http://dx.doi.org/10.1016/S0014-2999(01)00894-9
Access rights Closed access
Type Article
Web of Science ID WOS:000168220400004
URI http://repositorio.unifesp.br/handle/11600/26527

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