Abstract
The effect of Bay K 8644 on the contractile responses of the rat saphenous vein to KC1, noradrenaline, methoxamine, and B-HT 920 were studied. In all cases, Bay K 8644 potentiated the responses. These results confirmed the suggestion that α-adrenoceptor agonists initiated contraction in the rat saphenous vein by opening the potential-operated calcium channels.