Effect of NIP-142 on Potassium Channel α-Subunits Kv1.5, Kv4.2 and Kv4.3, and Mouse Atrial Repolarization

Abstract

Effects of NIP-142, a benzopyran compound which terminates experimental atrial arrhythmia, on potassium channel α-subunits and mouse atrial repolarization were examined. NIP-142 concentration-dependently blocked the outward current through potassium channel α subunits Kv1.5, Kv4.2 and Kv4.3 expressed in Xenopus oocytes. In isolated mouse atrial myocardia, NIP-142 prolonged the action potential duration and effective refractory period, and increased the contractile force. These results suggest that NIP-142 blocks the potassium channels underlying the transient and sustained outward currents, which may contribute to its antiarrhythmic activity.