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α 1 ‐adrenoceptor subtype(s) mediating noradrenaline‐induced contractions of the guinea‐pig aorta
Author(s) -
Oriowo MA
Publication year - 1994
Publication title -
fundamental and clinical pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.655
H-Index - 73
eISSN - 1472-8206
pISSN - 0767-3981
DOI - 10.1111/j.1472-8206.1994.tb00801.x
Subject(s) - guinea pig , nifedipine , aorta , medicine , endocrinology , contraction (grammar) , intracellular , adrenergic receptor , biology , chemistry , calcium , receptor , biochemistry
Summary— The effect of α 1 ‐adrenoceptor subtype selective antagonists, WB 4101, SZL‐49 and chloroethylclonidine on noradrenaline‐induced contractions of the guinea‐pig aorta has been studied in an attempt to identify the α 1 ‐adrenoceptor subtype(s) involved in the response. Noradrenaline and SDZ NVI 085 induced contractions of the aorta. Noradrenaline‐induced contractions were competitively antagonised by WB 4101 (pA 2 = 8.92, slope = 1.05). The contractions were significantly reduced by SZL‐49 but not by chloroethylclonidine, indicating an action on α 1A ‐adrenoceptor subtype. Noradrenaline‐induced contractions of the aorta were not inhibited by nifedipine (10 −6 M). The results are interpreted to suggest that α 1A ‐adrenoceptor subtype mediates noradrenaline‐induced contractions of the guinea‐pig aorta and that activation of α 1A ‐adrenoceptor subtype in the guinea‐pig aorta is probably linked to intracellular Ca ++ release.