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目的观察茶多酚(tea polyphenols,TP)对豚鼠心肌细胞L型钙通道电流(ICa-L)及动作电位的影响。方法采用常规微电极和全细胞膜片钳技术记录豚鼠心肌细胞ICa-L和动作电位。结果①不同浓度的TP均能缩短复极50%和90%水平的动作电位时程(APD50,APD90)。②不同浓度的TP明显抑制ICa-L,5,10,15 mg.L-1的TP使ICa-L的峰电流密度从(12.84±1.36)pA/pF减少到(10.24±1.47),(8.84±1.39),(6.65±0.56)pA/pF(n=6,P<0.01)。结论TP通过抑制心肌细胞钙内流使动作电位位时程缩短。
Objective To investigate the effects of tea polyphenols (TP) on L-type calcium channel current (ICa-L) and action potential in guinea pig cardiomyocytes. Methods The ICa-L and action potential of guinea pig cardiomyocytes were recorded by conventional microelectrode and whole-cell patch-clamp technique. Results ① TP at different concentrations shortened the APD50 and APD90 at 50% and 90% levels of repolarization. (2) TP of 5,10,15 mg.L-1 significantly inhibited ICa-L peak current density from (12.84 ± 1.36) pA / pF to (10.24 ± 1.47), (8.84 ± 1.39), (6.65 ± 0.56) pA / pF (n = 6, P <0.01). Conclusion TP can shorten the duration of action potentials by inhibiting calcium influx in cardiomyocytes.