Evidence for the role of alpha1D- and alpha1A-adrenoceptors in contraction of the rat mesenteric artery.
Vascul Pharmacol
; 40(2): 91-6, 2003 Feb.
Article
em En
| MEDLINE
| ID: mdl-12646397
ABSTRACT
We investigated the alpha(1)-adrenoceptor subtype(s) involved in contraction of the isolated rat mesenteric artery by the use of the agonists noradrenaline (NA), phenylephrine (PHE), oxymetazoline (OXY), and methoxamine (MET), the competitive antagonists 8-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-8-azaspiro(4.5)decane-7,9-dione dihydrochloride (BMY 7378) and 5-methylurapidil, and the alkylating agent chloroethylclonidine (CEC). Agonists showed the potency order NA> or =PHE>OXY>MET; pA(2) values for 5-methylurapidil and BMY 7378 were 7.74+/-0.11 and 8.72+/-0.28, respectively, while Schild slopes were not different than unity; alpha(1)-adrenoceptor alkylation with CEC showed a drastic decrease in maximal agonists-induced contraction and a shift to the right of about 46-, 122-, 2-, and 15-fold higher than controls for NA, PHE, OXY, and MET, respectively. Data suggest that alpha(1D)-adrenoceptors predominate for contraction in mesenteric artery of the Wistar rat, with a second population of alpha(1A)-adrenoceptors responding at high agonist concentrations.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Clonidina
/
Receptores Adrenérgicos alfa 1
/
Artérias Mesentéricas
/
Músculo Liso Vascular
Limite:
Animals
Idioma:
En
Ano de publicação:
2003
Tipo de documento:
Article