通络药物对心肌细胞钠钙离子通道的影响

Effects of solution of dry powder of ShenSongYangXin capsule on sodium current and L-type calcium current in ventricular myocytes:experiment with guinea pig

目的观察通络药物参松养心胶囊提取干粉溶液对单个豚鼠心室肌细胞膜钠通道电流(I_(Na))、L 型钙通道电流(I_(Ca,L))的影响。方法用钙外液将参松养心胶囊干粉配制成不同浓度(1%、0.5%、0.25%)。用酶解法分离单个心室肌细胞,并用全细胞膜片钳记录技术记录电流。结果当药物浓度0.5%时,可以使 I_(Na)峰值电流密度从(27.2±5.4)pA/pF 降至(14.9±2.8)pA/pF,平均抑制率为44.8%±7.7%(n=5,P<0.05);药物浓度为1%,0.5%,0.25%时,分别对 I_(Ca,L)的峰值电流密度的抑制率为50.7%±5.6%,44.8%±6.5%,和19.2%±1.1%,(n=5,P<0.05)。药物可以使 I_(Na)、I_(Ca,L)的电流密度-电压曲线上移,但均不改变其激活、峰值和反转电位。结论参松养心胶囊提取干粉溶液对 I_(Na)、I_(Ca,L)具有阻滞作用,这可能是其抗心律失常和心肌保护作用药理机制的一部分。

Objective To investigate the effects of dry powder of ShenSongYangXin capsule on sodium current （INa） and L-type calcium current （ICa,L） in ventricular myocytes. Methods Ventricular myecytes were isolated from guinea pig. Solution of the dry powder of ShensongYangXin capsule of the concentrations of 1%, 0.5%, and 0. 25% was added into the suspension of the myecytes. Whole cell patch-clamp technique was used to detect the INA and ICa,L in the ventricular myecytes. Result ShenSongYangXin decreased the peak INa from 27.2 ＋ 5.4 （ pA/pF ） to 14.9 ＋ 2.8 （ pA/pF ）,with a decrease rate of 44.8% ＋ 7.7 % （ n =5 , P 〈0.05） . The solution of dry powder of ShenSongYangXin of the concentrations of 1%, 0.5%, and 0. 25% decreased the peak L-type calcium channel current （Ca,L） significantly in a concentration dependent manner with the reduction rates of 50. 7% ＋ 5.6% , 44.8% ＋ 6.5%, and 19.2% ＋1.1% respectively （n=5, all P〈0. 05）. ShenSongYangXin shifted up both the I - 1V curve of INa and that of ICa,L, while their active, peak and reverse potentials didn＇t change. Conclusion ShensongYangXin blocks both INA and ICa,L, which may contributes to some of its antiarrhythmic effect.