Alpha1- and alpha2-adrenoceptors at different levels of the canine saphenous vein

• Tipo: Artigo em Livro de Atas de Conferência Internacional
• Data: 1991

Autores

guimaraes, s (Autor) Outra; moura, d (Autor) Outra; nunes, jp (Autor) FMUP; vaz-da-silva, mj (Autor) FMUP; guimaraes, jt (Autor) Outra

Ata de Conferência Internacional

Título: Journal of Neural Transmission, Supplement

Páginas: 163-169

Indexação

ISI Web of Knowledge

Scopus - 0 Citações

Outras Informações

ID Authenticus: P-007-5GD

Abstract (EN): Presynaptic alpha2- and postsynaptic alpha1-adrenoceptors were compared at the distal and proximal parts of the dog saphenous vein. The results obtained show that: (1) yohimbine is more effective against postsynaptic responses to phenylephrine distally than proximally. On the contrary, WB-4101 is more effective proximally; (2) phenylephrine increases inositol monophosphate production at both levels, but the increase is more pronounced distally; (3) UK-14,304 and adrenaline reduce and yohimbine and phentolamine increase the release of 3H-noradrenaline caused by electrical stimulation at both levels. However, while adrenaline as well as the antagonists are equipotent at the two levels, UK-14,304 is more potent distally than proximally. In conclusion, we suggest that: more alpha(1A)-adrenoceptors exist distally than proximally; imidazoline sites can exist at the distal level which contribute to the higher potency of UK-14,304 distally.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 7