亮啡肽对离体大鼠心室肌细胞膜功能的抑制作用

The inhibitory effects of leu-enkephalin on ventricular muscle cell membrane function from rats

本实验采用分离的SD大鼠心室肌细胞，以Fura－2AM负载，芝光分光光度计测试心室肌细胞内游离钙浓度的变化，观察亮啡肽对心室肌细胞内游离钙浓度的变化影响。实验结果表明：①亮啡肽可抑制由KCI引起的心室肌细胞膜上电压依赖性钙通道开放。②亮啡肽可抑制由去甲肾上腺素（NE）引起的心室肌细胞膜上受作依赖性钙通道开放。③亮啡肽可抑制心室肌细胞膜上钙泵的活动，使由咖啡因引起的内钙释放不能及时地排出。亮啡肽的以上作用是由心室肌细胞内抑制性G蛋白介导的。

To observe the inhibitory effects of Leu-enkephalin(LEK) Con ventricu-lar muscle cell function, the ventricular muscle cells separated from SD rats were loaded on Fura-2AM, and the concentration of tree Calcium was measured by fluo-rescence spectrophotometer assay. The results of the experiment showed that (1)LEK can inhibit the opening of voltage-dependent Calcium channel (VDC) on the heart muscle cell membrane caused by KCL. (2) LEK can inhibit the opening of re-ceptor-operated Calcium channel (ROC) on the heart muscle cell membrane caused by norepinephrine (3) LEK can inhibit the activities of the Calcium pump on the cell membrane, thus delaying the inner Calcium elimination caused by caffeine. The above mentioned effects of LEK were mediated through the inhibitory protein G in the heart muscle cells.