艾司洛尔对人诱导多能干细胞来源心肌细胞自发动作电位的影响

Effects of esmolol on spontaneous action potential of human-induced pluripotent stem cell-derived cardiomyocytes

目的探讨艾司洛尔对人诱导多能干细胞来源心肌细胞(hiPSC-CM)自发动作电位的影响。方法选择培养60 d的hiPSC-CM,提取单个心肌细胞,应用膜片钳技术建立全细胞记录模式。采用动作电位细胞外液或起搏电流细胞外液将艾司洛尔稀释至100μmol/L,灌流速度3 ml/min,灌流量10 ml。分别于给药前(T_0)、给药后5 min(T_1)和冲洗后5 min(T_2)时记录自发动作电位的频率、静息电位、阈电位、振幅、90%复极时间、超极化电位、超极化后复极时间和起搏电流。结果与T_0时比较,T_1时hiPSC-CM自发动作电位的频率升高,振幅和超极化电位降低,90%复极时间和超极化后复极时间缩短(P<0.05),hiPSC-CM起搏电流-钳制电压曲线无明显移位(P>0.05)。与T_1时比较,T_2时hiPSC-CM自发动作电位的频率降低,振幅和超极化电位升高,90%复极时间和超极化后复极时间延长(P<0.05),hiPSC-CM起搏电流-钳制电压曲线无明显移位(P>0.05)。不同时点hiPSC-CM自发动作电位的静息电位和阈电位比较差异无统计学意义(P>0.05)。结论艾司洛尔可增加hiPSC-CM的自发动作电位节律,其机制可能与起搏电流无关。

Objective To investigate the effects of esmolol on spontaneous action potential of human-induced pluripotent stem cell-derived cardiomyocytes(hiPSC-CM).Methods Whole-cell patch-clamp recording was established in single hiPSC-CM cultured for 60 days.Esmolol was diluted to 100μmol/L with extracellular solution of action potential or pacemaker current and applied 10 ml every time at a rate of 3 ml/min.T_he frequency of spontaneous action potential,rest membrane potential,threshold potential,amplitude,90%repolarization of action potential(APD90),super-polarization potential,repolarization time after super-polarization,and pacemaker current were recorded before administration(T_0),5 min after administration(T_1),and 5 min after washing(T_2).Results Compared with that at T_0,the frequency of spontaneous action potential was significantly increased at T_1,the amplitude and super-polarization potential were decreased at T_1,APD90 and repolarization time after super-polarization was shortened at T_1(P<0.05),and no significant shift was found in current-voltage curves of pacemaker currents at T_1(P>0.05).Compared with that at T_1,the frequency of spontaneous action potential was significantly decreased at T_2(P<0.05),the amplitude and super-polarization potential were increased at T_2,APD90 and repolarization time after super-polarization was prolonged at T_2(P<0.05),and no significant shift was found in current-voltage curves of pacemaker currents at T_2(P>0.05).T_here were no significant differences in rest membrane potential and threshold potential of action potential among different time points(P>0.05).Conclusion Esmolol can increase the spontaneous action potential rhythm of hiPSC-CM,and the mechanism may not be related to pacemaker currents.