黄芪总黄酮对急性心肌梗死大鼠心室肌细胞L-型钙电流及钠电流的作用

目的研究黄芪总黄酮（TFA）对急性心肌梗死（Am）大鼠心室肌细胞L-型钙电流（L—ICa）及钠电流（INa）的作用。方法设正常对照组、AMI组及TFA实验组。大鼠开胸左前降支结扎造成AMI，开胸前5min实验组大鼠舌静脉注射剂量为20mg／kg的TFA溶液50ul。用胶原酶酶解法急性分离AMI模型大鼠心室肌细胞，采用全细胞膜片钳记录技术记录左前降支供血区心外膜细胞的L—ICa及INa的作用。结果①应用TFA（20mg／kg）后，L—ICa从（0．313±0．14）nA增加到（0．402±0．27）nA，差异有统计学意义（P〈0．01，n=6）。②应用TFA（20mg／kg）后与对照组比较，峰值从（-8．43±2，03）nA下降到（-6．37±1．58）nA，差异有统计学意义（P〈0．01，n=6）。结论TFA可以增加AMI大鼠心室肌细胞L—ICa的幅值，TFA可显著降低AMI大鼠心室肌细胞INa的幅值。

The effects of totalfiavonoids of astragalus(TFA)on the L-type Ca2+ current and the sodium current of the ventricular myocytes after the acute myocardial infarction

Objective To study the effect of totalflavonoids of astragalus （TFA） on the L-type Ca^2＋current and the sodium current of guinea pig isolated ventficular myocytes after the acute myocardial infarction. Methods The rats were divided into control, AMI and TFA groups. In TFA group, the pigs were injected from tongue vein first, and then ligated LAD. Whole cell patch clamp technique was applied to record the L-calcium current（L-Ica） and the sodium current of rat isolated ventficular myocytes from ischemic zone adjacent to infarcted area. Results （1）L-ICa of TFA（20 mg/kg）enhanced from （0.313±0.14）nA to （0.402±0.27）nA. There is significant difference compared to control group（P〈0.01 ,n=6）.（2） I Na of TFA（20 mg/kg）decreased from （-8.43±2.03） nA to （ -6.37 ± 1.56 ）nA, there was significant difference compared to control group （P〈0.01, n =6 ）. Conclusion TFA enhances the L-type Ca^2＋ current of ventricular myocyte after the acute myocardial infarction, and inhibit the sodium current of ventricular myocyte after the acute myocardial infarction.