Pretreatment with aspirin does not influence the pressor response to α2-adrenoceptor agonists in conscious rabbits

Abstract

Abstract It has proved relatively easy to demonstrate pressor responses mediated via α2-adrenoceptors in-vivo and in whole blood perfused vascular beds, but not in in-vitro work. The possibility that platelet α2-adrenoceptor activation, with subsequent release of vasoactive prostanoids, contributes to the pressor response to α2-adrenoceptor agonists was investigated. The pressor response to the α2-adrenoceptor agonist BHT 920 (Alefexole) was compared in rabbits pretreated with distilled water or aspirin (3 times 200 mg kg−1 by gavage). Aspirin pretreatment had no significant effect on responses to BHT 920; thus, prostanoid formation does not appear to be an important mechanism contributing to postsynaptic α2-adrenoceptor activation.