三七皂苷Fc对SD大鼠心室肌细胞钠离子通道电流的影响

Effects of Notoginsenoside Fc on Sodium Ion Channel Currents in Ventricular Myocytes of SD Rats

关键词:  三七皂苷Fc  膜片钳  钠通道  心室肌细胞  SD大鼠

Key words:  notoginsenoside Fc  patch clamp  sodium channel  ventricular myocytes  SD rats

摘要:

目的 探究三七皂苷Fc (notoginsenoside Fc，N-Fc)对SD大鼠心室肌细胞钠离子通道电流的影响。方法 使用Langendorff恒温恒压灌流装置通过酶解法急性分离SD大鼠心室肌细胞，采用标准全细胞膜片钳技术观察并记录不同浓度的N-Fc对大鼠心室肌细胞钠通道电流(I_Na)及其动力学特征的影响。结果 5µmol·L^–1的N-Fc对I_Na无明显影响，随着药物浓度的增加，10，20，50µmol·L^–1的N-Fc可使钠峰值电流由给药前的(–87.49±3.40) pA/pF依次下降为(–62.91±2.37)，(–49.30±1.27)，(–34.68±3.21) pA/pF (P<0.01)；I_Na的I-V曲线上移，但形态轨迹、激活电位及峰电位基本不变；I_Na的激活曲线向去极化方向迁移，半数激活电压由给药前的(–52.37 ±1.32) mV变为(–42.74 ±0.37)，(–38.92 ±2.77)，(–33.78 ±0.96) mV (P<0.05)；失活曲线显著左移，半数失活电压(V_1/2-in)由(–55.95±4.88) mV依次变为(–64.29 ±1.77)，(–69.57±3.47)，(–73.32±3.79) mV (P<0.05)；此外，N-Fc能够显著延长I_Na失活后恢复时间，时间常数τ值(给药前，10，20，50µmol·L^–1N-Fc处理后)分别为(12.50±1.17)，(21.36±2.23)，(25.35±1.25)，(34.35±1.24) ms (P<0.05)。结论 N-Fc能浓度依赖性地抑制SD大鼠心室肌细胞的I_Na，并能显著影响其激活、失活及失活后恢复的动力学特征。

Abstract:

OBJECTIVE To explore the effects of notoginsenoside Fc(N-Fc) on sodium ion channel currents of ventricular myocytes in SD rats. METHODS Ventricular myocardial cells were enzymatically isolated from SD rats by Langendorff with constant pressure and temperature, the whole-cell patch clamp techniques were used to observe and record the effects of I_Na and its kinetics in ventricular mgocytes of SD rats treated with different concentrations of N-Fc. RESULTS There was no significant effect on I_Na when the concentration of N-Fc was 5 µmol·L^–1, with the increase of drug concentration, the peak sodium current was decreased from (–87.49±3.40)pA/pF to (–62.91±2.37), (–49.30±1.27), (–34.68±3.21)pA/pF(P<0.01) under the effects of 10, 20 and 50 µmol·L^–1 N-Fc. I-V curve of I_Na were shifted upward, but the morphological trajectories, activation potential and peak potential did not change. The activation curve of I_Na were shifted to the depolarization direction, and the half in activation voltage was changed from (–52.37 ±1.32)mV to (–42.74 ±0.37), (–38.92 ±2.77), (–33.78 ±0.96)mV(P<0.05). The inactivation curve shifted significantly to the left, the half inactivation voltage changed from (–55.95±4.88)mV to (–64.29±1.77), (–69.57±3.47), (–73.32±3.79)mV(P<0.05). In addition, N-Fc significantly prolonged the recovery time after I_Na inactivation, and the time constant τ(before administration, after treated with 10, 20, 50 µmol·L ^-1N-Fc) were (12.50±1.17), (21.36±2.23), (25.35±1.25), (34.35±1.24)ms(P<0.05). CONCLUSION N-Fc can inhibit I_Na of SD rats ventricular myocytes in a concentration-dependent manner and it has an significant effect on the kinetics characteristics of activation, inactivation and recovery.