目的 观察茶多酚(teapolyphenols,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/Ca-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-L5,10,15mg·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)M/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 effects of tea polyphenols (TP) on ICa-L in guinea pig myocardial ceils. METHODS The standard microelectrode technique and whole-cell variant patch-clamp technique were used to record ICa-L and action potential in guinea pig myocardial cells. RESULTS The TP of different concentration shortened the action potential duration of repolarization (APD50 and APD90 ). The TP of different concentration inhibited ICa-L The application of 5, 10, 15 mg· L^-1 TP reduced the density of peaklc,_t, from (12.84±1.36) pA/pFto (10.24±1.47), (8.84±1.39), (6.65±0.56) pA/pF (n=6, P〈0.01). CONCLUSION TP could reduce action potential duration by inhibiting calcium current.