Erg K~+ channels modulate contractile activity in the bovine epididymal duct

摘要

The best-known function of an ergl current is its contribution to the repolarization of the cardiac action potential (31). E-4031 -sensitive currents have also been detected in SMC of the esophagus (1), portal vein (28), gallbladder (29), stomach (27) and intestine (8, 18, 20). It is assumed that, in SMC, erg currents serve the function of threshold currents; a pharmacological block of erg channels depolarizes the membrane potential, which is correlated with muscle contraction (see Ref. 34 for review). Within the intestinal musculature, erg channels are concentrated on the interstitial cells of Cajal and may play a crucial role in regulating their pacemaker frequency (41). Likewise, multiple ergl isoforms may constitute the molecular basis of pacemaker activity in sinoatrial node myocytes (5).