雷诺嗪对兔心房肌细胞快钠电流的影响及使用依赖性阻滞作用

Effect of ranolazine on the fast sodium channel current in rabbit atrial myocytes and use-dependent blockade

目的研究雷诺嗪对兔心房肌细胞快钠电流的影响及其是否存在使用依赖性阻滞作用。方法应用全细胞膜片嵌记录方法,了解雷诺嗪对兔单个心房肌细胞快钠电流的作用,及在不同刺激频率(1 Hz、3.3 Hz、5 Hz)时对快钠电流的影响。结果30μmmol/L雷诺嗪对兔心房肌细胞快钠电流有明显的抑制作用,其IC50为(25.6±1.8)μmmol/L,并且随着刺激频率的增加其作用加强,存在使用依赖性。结论雷诺嗪对兔心房肌细胞快钠电流有一定的抑制作用,其存在使用依赖性阻滞作用。

Objective To explore the effect of ranolazine on the fast sodium channel current （INa） in rabbit atrial myocytes and the existence of use-dependent blockade. Methods Standard whole cell patch clamp technique was used to study the effect of ranolazine on the fast sodium channel current and the use-dependent blockade caused with different frequencies （1 Hz, 3.3 Hz and 5 Hz） to stimulate the cells. Results The 30 μmol/L ranolazine significantly reduced INa with an IC50 value of （25.6± 1.8）μmmol/L and produced a frequency-dependent inhibitory effect on INa with obvious use-dependence. Gonclusion Ranolazine can inhibit the fast sodium channel current in rabbit atrial myocytes and indeed has a use-dependent effect.