Involvement of sensory nerves in vasodilator responses to acetylcholine and potassium ions in rat hepatic artery.
Br J Pharmacol
; 130(1): 27-32, 2000 May.
Article
em En
| MEDLINE
| ID: mdl-10780994
ABSTRACT
In the presence of ouabain (1 mM), acetylcholine and KCl (5 mM) evoked endothelium-independent relaxations in rat hepatic arteries. Treatment with capsaicin (10 microM), scopolamine (1 microM) or CGRP(8 - 37) (3 microM) prevented these relaxations. Acetylcholine-induced relaxations in intact arterial segments in the presence of indomethacin (10 microM) and N(G)-nitro-L-arginine (0.3 mM) were only partially inhibited by ouabain plus BaCl(2) (30 microM). However, ouabain plus BaCl(2) almost abolished such relaxations in capsaicin-pre-treated preparations. In arteries without endothelium, the neurosecretagogue alpha-latrotoxin (1 nM) induced complete relaxations, which were abolished by CGRP(8 - 37) or pre-treatment with capsaicin. alpha-Latrotoxin also induced a smooth muscle hyperpolarization (12+/-2 mV), which was abolished by CGRP(8 - 37). The ability of ouabain to disclose a CGRP-mediated neurogenic relaxation must be considered when this agent is used as a pharmacological tool. The results further suggest that CGRP is a nerve-derived hyperpolarizing factor in the rat hepatic artery.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Ouabaína
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Cloreto de Potássio
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Vasodilatadores
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Cardiotônicos
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Acetilcolina
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Artéria Hepática
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Neurônios Aferentes
Idioma:
En
Ano de publicação:
2000
Tipo de documento:
Article