a-Adrenoceptors and Calcium Activation Mechanisms in Vascular Muscle

Abstract

A pharmacological study was made of a-adrenoceptor mediated calcium activation mechanisms in the vascular
muscle of the rat. The portal vein was examined for the presence of postjunctional a-adrenoceptors. The results did not provide evidence for the existence of two subtypes of
a-adrenoceptor in this vessel.

In the pithed rat, pressor responses to continuous infusions of phenylephrine were resistant to diltiazem while those to UK-14,304 were attenuated. Pretreatment with
prazosin or with corynanthine revealed a diltiazem sensitive
component of the pressor response of the pithed rat to cirazoline. Yohimbine had no significant effect on the pressor response to cirazoline following treatment with
phenoxybenzamine, but, after prazosin, diltiazem attenuated
the response to the highest three doses of cirazoline tested.

Date of Award	Sept 1987
Original language	English
Awarding Institution	Aston University