An investigation of presynaptic α-adrenoceptor subtypes in the pithed rat heart

Abstract

1 The presynaptic cardio-inhibitory and postsynaptic pressor responses to the α-adrenoceptor agonists xylazine and cirazoline, and the interaction with the antagonists yohimbine and prazosin, were examined in the pithed rat. 2 Evidence was found to suggest that, as well as the already established pre- and postsynaptic α₂-and postsynaptic α₁-receptors, presynaptic α₁-receptors are present.