黄芪总黄酮对豚鼠心室肌细胞钾离子通道的作用

目的研究黄芪总黄酮(totalflavonoids of ast ragalus,TFA)对豚鼠心室肌细胞延迟整流钾电流(IK)、内向整流钾电流(IK1)的作用。方法胶原酶酶解法急性分离豚鼠心室肌细胞,利用全细胞膜片钳的方法记录心室肌细胞的延迟整流钾电流、内向整流钾电流。结果(1)应用TFA(20mg.kg-1)后IK从(1.21±0.24)nA降至(0.96±0.27)nA(P<0.01,n=6),而TFA(40mg.kg-1)组IK从(1.45±0.36)nA下降到(1.01±0.27)nA,差异有统计学意义(P<0.01,n=6)。(2)应用TFA(20mg.kg-1,40mg.kg-1)后与对照组比较,TFA(20mg.kg-1,40mg.kg-1)分别使内向整流钾电流(IK1)峰值从(-8.93±2.03)nA和(-8.83±1.56)nA下降到(-8.87±1.58)nA和(-8.54±1.37)nA,差异无统计学意义(P>0.05,n=6)。结论TFA可以降低豚鼠心室肌细胞延迟整流钾电流(IK)的幅度,呈剂量依赖性。TFA对豚鼠心室肌细胞内向整流钾通道(IK1)作用不明显。

The effects of totalflavonoids of astragalus on potassium channel of guinea pig ventricular myocardial cells

Objective To study the effects of totalflavonoids of astragalus(TFA) on the delayed rectifier potassium current(IK) and the inward rectifier potassium current(IK1) in guinea pig isolated ventricular myocardial cells.Methods Guinea pig ventricular myocardial cells were isolated and whole cell patch clamp technique was applied to record the IK and IK1.Results(1) Under 20 mg/kg TFA,IK significantly decreased from(1.18±0.27) nA to(0.94±0.25) nA(P< 0.01,n=6);under 40 mg/kg TFA,IK decreased from(1.42±0.33) nA to(1.01±0.29) nA(P< 0.01,n=6).(2) Under 20 mg/kg TFA,IK1 decreased from(-8.93±2.03)nA to(-8.83±1.56)nA(P>0.05,n=6);under 40 mg/kg TFA,IK1 decreased from(-8.87±1.58) nA to(-8.54±1.37) nA(P>0.05,n=6).Conclusions TFA remarkably inhibits IK in guinea pig ventricular myocardial cells with a dose-dependence pattern;while it shows no effect on IK1.