Résumé
Aim To investigate the direct effects and mechanism of carvedilol on HERG channel stably expressing in human embryonic kidney-293(HEK293) cells.Methods Whole-cell patch-clamp technique was used to record HERG current and kinetic curves in single cells.Western blot methods were used to investigate the expression of HERG channel in different concentration of carvedilol.Result Carvedilol decreased HERG current in a concentration-dependent manner with an IC50 539.6 nmol?L-1,Hillslope-0.64.The time constants of onset of inactivation and deactivation were accelerated.Other kinetcs(activation,inactivation,recovery from inactivation)had no significant changes.Based on western result,carvedilol had no effect on the generation and trafficking of HERG protein.Conclusion Carvedilol inhibits the transfected HERG channels by influencing the open state which is the probable anti-arrhythmic mechanism.There is no relationship between carvedilol and HERG channel expression.