Involvement of voltage-dependent potassium channels in the EDHF-mediated relaxation of rat hepatic artery
1. In the rat hepatic artery, the acetylcholine-induced relaxation mediated by endothelium-derived hyperpolarizing factor (EDHF) is abolished by a combination of apamin and charybdotoxin, inhibitors of small (SK(Ca)) and large (BK(Ca)) conductance calcium-sensitive potassium (K)-channels, respectively, but not by each toxin alone. The selective BK(Ca) inhibitor iberiotoxin cannot replace charybdot