Role of Ca2+-Activated K+ Channels on Adrenergic Responses of Human Saphenous Vein

The results suggest that large conductance Ca2+-activated K+ channels are activated by stimulation with norepinephrine to counteract the adrenergic-induced contractions of human saphenous vein. Thus, inhibition of these channels increases significantly the contraction, an effect that appears to be mediated by an increase in Ca2+ entry through L-type voltage-dependent Ca2+ channels.