乌苏里藜芦生物碱对豚鼠心肌细胞动作电位及钙电流的影响

Effects of Vera-U alkaloids on action potential and calcium current of cardiac myocytes in guinea pigs

的 研究乌苏里藜芦生物碱对豚鼠心肌细胞动作电位及钙通道电流的作用。方法 用全细胞记录技术记录单个心室肌细胞动作电位以及钙通道电流。结果 乌苏里藜芦生物碱可延长动作电位时程 ,其在 0 3～ 30 μmol·L- 1 的浓度范围内 ,可使复极 90 %动作电位时程 (APD90 )和复极 50 %动作电位时程 (APD50 )分别延长 1 3%～ 1 1 2 %和 2 3 %～ 1 31 %。 3～ 30 μmol·L- 1 的高浓度可诱发异常节律。乌苏里藜芦生物碱对心肌细胞钙电流有促进作用 ,此作用呈短暂的浓度依赖性增强。结论 乌苏里藜芦生物碱可通过增加钙通道电流延长心室肌细胞动作电位时程。

Objective To study the effect of alkaloids of Veratrum Nigrum L. Var. Ussuriense Nakai (Vera U alkaloids) on the action potential and the calcium current in guinea pig's cardiac myocytes. Methods After myocardiocytes were isolated from 23 guinea pigs, Vera U alkaloid at 0.3, 3 and 30 μmol/L were added respectively in the culture medium. The action potentials and the calcium current in single cardiac myocyte were recorded with whole cell patch clamp recording techniques. Results Vera U alkaloids significantly lengthened the action potential duration (APD). The 50% and 90% repolarization (APD 50 and APD 90 ) were prolonged from 23% to 131% and from 13% to 112% respectively when the concentrations of Vera U alkaloids ranged from 0.3 to 30 μmol/L. The abnormal rhythm was evoked at higher concentration. Vera U alkaloids developed an enhancement effect on calcium current (I ca ) in a temporary concentration dependent manner. Conclusion Vera U alkaloids prolong APD, especially APD 50 , and raise the excitability of cardiomyocytes by enhancing of the calcium current.