EFFECTS of ENDOTHELIN-1 ON the ISOLATED GUINEA-PIG ILEUM - ROLE of NA+ IONS

EFFECTS of ENDOTHELIN-1 ON the ISOLATED GUINEA-PIG ILEUM - ROLE of NA+ IONS

Autor Miasiro, N. Google Scholar
Paiva, ACM Google Scholar
Instituição Universidade Federal de São Paulo (UNIFESP)
Resumo Endothelin-1 induced an unusual transient biphasic effect (relaxation followed by contraction) in the isolated guinea-pig ileum. the contractile component of the response was concentration-dependent in the dose range studied, but the relaxant component was not. Neuronal mechanisms and cyclic GMP do not seem to be involved in the relaxing effect since this component was not affected by either tetrodotoxin, atropine or methylene blue. Endothelin-1 induced desensitization which was well characterized for the contractile component of the response, and was only partially reversed after a 3-h resting period. the effects of endothelin-1 were particularly sensitive to decreases in the Na+ gradient induced either by lowering the Na+ concentration in the medium or by treating the tissue with ouabain or by a previous treatment with acetylcholine. Amiloride partially inhibited the response induced by endothelin-1 indicating that Na+ channels and/or Na+ /H+ exchange are probably involved in its action. Our results suggest that the contractile response induced by endothelin-1 in the isolated guinea-pig ileum depends greatly on Na+ ions, in contrast to the responses observed in vascular smooth muscle.
Palavra-chave ENDOTHELIN-1
GUINEA-PIG ILEUM
DESENSITIZATION
SODIUM IONS
Idioma Inglês
Data de publicação 1990-12-01
Publicado em Naunyn-schmiedebergs Archives of Pharmacology. New York: Springer Verlag, v. 342, n. 6, p. 706-712, 1990.
ISSN 0028-1298 (Sherpa/Romeo, fator de impacto)
Publicador Springer
Extensão 706-712
Fonte http://dx.doi.org/10.1007/BF00175716
Direito de acesso Acesso restrito
Tipo Artigo
Web of Science WOS:A1990EV73600014
Endereço permanente http://repositorio.unifesp.br/handle/11600/25170

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