Objectives The effects of car-vedilol on calcium current (ICa) were investigated inisolated adult rat ventricular myocytes. Methods ICawas recorded by using whole-cell patch-clamp recordingtechnique. Results Carvedilo...Objectives The effects of car-vedilol on calcium current (ICa) were investigated inisolated adult rat ventricular myocytes. Methods ICawas recorded by using whole-cell patch-clamp recordingtechnique. Results Carvedilol reversibly inhibited ICain a concentration-dependent manner, carvedilol at 0.1,0.3, 1 and 10 μmol/L in the extracellular solution dec-reased peak ICa by 1.52%, 18.04%, 37.34%and72.18%,respectively. The steady-state inactivation curve of ICawas shifted to more negative potentials, while the activ-ation curve was not altered. The recovery from inactiva-tion was shifted to right direction, it could not berecovered completely. In addition, Pretreatment ofventricular myocytes with prazosin and propranololcouldn't block the carvedilol-induced reduction of ICa.Conclusions Carvedilol inhibits I C a i n adult ratventricular myocytes by mechanisms involvingpreferential interaction with the inactivated state ofcalcium channel.展开更多
文摘Objectives The effects of car-vedilol on calcium current (ICa) were investigated inisolated adult rat ventricular myocytes. Methods ICawas recorded by using whole-cell patch-clamp recordingtechnique. Results Carvedilol reversibly inhibited ICain a concentration-dependent manner, carvedilol at 0.1,0.3, 1 and 10 μmol/L in the extracellular solution dec-reased peak ICa by 1.52%, 18.04%, 37.34%and72.18%,respectively. The steady-state inactivation curve of ICawas shifted to more negative potentials, while the activ-ation curve was not altered. The recovery from inactiva-tion was shifted to right direction, it could not berecovered completely. In addition, Pretreatment ofventricular myocytes with prazosin and propranololcouldn't block the carvedilol-induced reduction of ICa.Conclusions Carvedilol inhibits I C a i n adult ratventricular myocytes by mechanisms involvingpreferential interaction with the inactivated state ofcalcium channel.
