心肌肽素对急性心肌梗死大鼠心脏血流动力学及心肌细胞钙电流的作用

目的探讨心肌肽素（cardiomyopeptidi）对急性心肌梗死（AMI）大鼠心脏血流动力学及心肌细胞钙电流的作用。方法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浓度为50μg／ml的心肌肽素溶液50μl，并设正常对照组、AMI组及心肌肽素实验组，行血流动力学检查；酶解分离心室肌细胞，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型Ca^2＋电流（L—Ica）的作用。结果应用心肌肽素（50p,g／m1）后与AMI组比较，血流动力学指标明显改善（P〈0．05，n=7）。②应用心肌肽素（50μg／m1）后，L-型钙电流（L—ICa）由给药前的（0．15±0．34）nA增加到给药后的（0．31±0．37）nA（P〈0．01，n=7）。结论心肌肽素可以明显改善AMI大鼠心脏血流动力学，可以增加AMI大鼠心室肌细胞L-型钙电流的幅值。

The effect of cardiomyopeptidi on the hemodynamic of the left ventricula and calcium current of ventricular myocytes after acute myocardial infarction

Objective To study the effect of cardiomyopeptidi on the hemodynamic of the left ventricular and on calcium current of ventricular myocytes after the acute myocardial infarction. Methods The acute myocardium infarction models of rat were prepared by ligaturing the LAD of coronary artery. The rat was divided into control group, AMI group and cardiomyopeptidi group by injection cardiomyopeptidi from tongue vein. The changes of LVP and LVdp/dtmax were measured, and L-calcium current （L-Ica） of isolated ventricular myocytes from ischemic zone adjacent to infarcted area were measured by cell patch clamp technique. Results （1）Compared with the AMI group, the hemodynamic of the left ventricula after the acute myocardial infarction was significantly enhanced in cardiomyopeptidi（50μg/ml） group （P〈0.05, n=7 ）. （2）Compared with AMI group, the calcium current increased from （0.15±0,34）nA to （0,31±0.37）nA in cardiomyopeptidi （50 μg/ml） （P〈0.01, n=7 ）, Conclusion Cardiomyopeptidi can significantly improve the hemodynamic of the left ventricular after the acute myocardial infarction, and enhance the L-calcium current of ventricular myocytes after the acute myocardial infarction.