EFFECTS OF ENDOTHELIN-1 AND ENDOTHELIN-3 ON THE ISOLATED GUINEA-PIG ILEUM - ROLE OF NA+ IONS AND ENDOTHELIN RECEPTOR SUBTYPES

EFFECTS OF ENDOTHELIN-1 AND ENDOTHELIN-3 ON THE ISOLATED GUINEA-PIG ILEUM - ROLE OF NA+ IONS AND ENDOTHELIN RECEPTOR SUBTYPES

Author Miasiro, N. Autor UNIFESP Google Scholar
Paiva, Antonio Cechelli de Mattos Autor UNIFESP Google Scholar
Institution Universidade Federal de São Paulo (UNIFESP)
Abstract Endothelin (ET)-1 and ET-3 induced a biphasic effect (relaxation followed by contraction) in the isolated guinea pig ileum. The contractile but not the relaxant component of the responses was concentration dependent in the dose range studied. Neuronal mechanisms, cyclic guanosine monophosphate (GMP), and adenosine triphosphate (ATP)-dependent K+ channels do not seem to be involved in the relaxing effect of the two isopeptides, since that effect was not affected by either tetrodotoxin, methylene blue, or glibenclamide. Both ET-1 and ET-3 induced tachyphylaxis (homologous desensitization), which was not fully reversed after a 3-h resting period. The responses to both peptides were dependent on the Na+ gradient across the smooth muscle cells, as they were inhibited in low-Na+ medium and after treatment of the preparation with ouabain. Verapamil affected both the relaxant and the contractile components of the responses to the two isopeptides, whereas phorbol-12,13-dibutyrate affected mainly the contractile component. These results suggest that the voltage-operated channels are important for both components of the response induced by ET-1 and ET-3, and that protein kinase C may downregulate Ca2+ signalling. Cross-tachyphylaxis studies between ET-1 and ET-3 suggest the existence of at least two ET receptor subtypes in the guinea pig ileum.
Keywords ENDOTHELIN-1
ENDOTHELIN-3
GUINEA PIG ILEUM
DESENSITIZATION
NA+ IONS
ENDOTHELIN RECEPTOR SUBTYPES
Language English
Date 1992-01-01
Published in Journal Of Cardiovascular Pharmacology. Philadelphia: Lippincott-raven Publ, v. 20, p. S37-S40, 1992.
ISSN 0160-2446 (Sherpa/Romeo, impact factor)
Publisher Lippincott-raven Publ
Extent S37-S40
Origin http://journals.lww.com/cardiovascularpharm/Abstract/1992/04002/Effects_of_Endothelin_1_and_Endothelin_3_on_the.12.aspx
Access rights Open access Open Access
Type Article
Web of Science ID WOS:A1992KF28300012
URI http://repositorio.unifesp.br/11600/44221

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