Regional differences in the adenosine A(2) receptor-mediated modulation of contractions in rat vas deferens

• Tipo: Artigo em Revista Científica Internacional
• Data: 2003

Autores

Diniz, C (Autor) FFUP; Leal, S (Autor) Outra; Goncalves, J (Autor) FFUP

Revista

Título: European Journal of Pharmacology

Vol. 460

Páginas: 191-199

ISSN: 0014-2999

Editora: Elsevier

Indexação

ISI Web of Knowledge - 12 Citações

Scopus - 14 Citações

Classificação Científica

FOS: Ciências médicas e da saúde > Medicina básica

Outras Informações

ID Authenticus: P-000-J02

DOI: 10.1016/s0014-2999(02)02926-6

Abstract (EN): Adenosine receptors involved in modulation of contractions were characterized in the bisected rat vas deferens by combining pharmacological and immunohistochemical approaches. In both portions, noradrenaline-elicited contractions were enhanced by the adenosine A, receptor agonist N-6-cyclopentyladenosine (CPA), and inhibited by the non-selective adenosine receptor agonist 5'-N-ethylcarboxamidoadenosine (NECA) in the presence of the adenosine A(1) receptor antagonist 1,3-dipropyl-8-cyclopentyl-1,3-dipropylxanthine (DPCPX). The adenosine A(2A) receptor agonist 2-p-(2-carboxyethyl)phenethyl-amino-5'-N-ethylcarboxamidoadenosine (CGS 21680) also inhibited noradrenaline-elicited contractions but only in the prostatic portion. Contractions elicited by the stable ATP analogue alpha,beta-methyleneATP (alpha,beta-MeATP) were inhibited only by NECA in the presence of DPCPX and only in the prostatic portion. This study provides functional evidence for the presence, in both portions of the rat vas deferens, of an adenosine A I receptor-mediated enhancement and of an adenosine A(2) receptor-mediated inhibition of contractions. The latter effect is mediated by both A(2A) and A(2B) subtypes in the prostatic portion but only by the A(2B) subtype in the epididymal portion. This regional variation is supported by the immumohistochemical results that revealed an adenosine AIA receptor immunoreactivity not co-localized with nerve fibres more abundant in the prostatic than in the epididymal portion.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 9