目的 :探讨救心复脉注射液 (枳实提取液 )有效成分辛弗林 (311)、N 甲基酪胺 (4 17)对豚鼠心室肌细胞膜L型钙通道电流 (ICa L)的影响。方法 :用酶解法分离单个心室肌细胞 ,采用全细胞膜片钳技术 ,观察辛弗林、N 甲基酪胺对豚鼠心室肌细胞膜ICa L的影响。结果 :用辛弗林 (10 ,2 5 ,5 0 ,10 0mmol/L)时能增大ICa L,增加率分别为 8.2 7% ,2 7.2 9% ,4 1.0 1%和 4 8.74 % (P <0 .0 5 )。用N 甲基酪胺 (10 ,2 5 ,5 0 ,10 0mmol/L)时能增大ICa L,增加率分别为 10 .0 5 % ,30 .12 % ,4 3.0 5 %和 5 1.90 % (P <0 .0 5 )。辛弗林和N 甲基酪胺只改变电流幅度 ,不改变I V曲线形状。结论 :辛弗林和N 甲基酪胺有浓度依赖性的增大豚鼠心室肌细胞ICa L,促进钙通道开放的作用 Objective : To investigate the effects of Xinfufumai injection (Fructus Aurantii extract), synephrine (311) and N-methyltyramine (4 17), on L-type calcium channel current (ICa L) in guinea pig ventricular myocytes. METHODS: Single ventricular myocytes were isolated by enzymatic hydrolysis. Whole cell patch clamp technique was used to observe the effects of synephrine and N-methyltyramine on ICa L in guinea pig ventricular myocytes. Results: ICa L increased with synephrine (10, 25, 50, 100 mmol/L), with an increase rate of 8.2 7%, 27.2%, 4 1.0 1%, and 48.74% (P, respectively). <0 .0 5 ). The ICa L increased with N-methyltyramine (10, 25, 50, 100 mmol/L), and the increase rates were 10.0 5 %, 30.12 %, 4 3.0 5 %, and 5 1.90 %, respectively. (P <0. 0 5). Simfolin and N-methyltyramine only change the current amplitude without changing the I V curve shape. Conclusion: Simfolin and N-methyltyramine have a concentration-dependent increase in ICa L in guinea pig ventricular myocytes and promote the opening of calcium channels.