阜外极化液对缺血再灌注乳鼠心肌细胞快钠通道电流的影响

目的探讨阜外极化液(Fuwai polarizing solution,FW)对缺血再灌注心肌细胞快钠通道(INa)的影响。方法实验分为缺血再灌注组(I/R)、Histidine-tryptophan-ke toglutarat液组(HTK)和阜外极化液组(FW)。选择培养至18-48h的SD乳鼠心肌细胞用于实验。I/R组细胞经模拟缺血缺氧3h、再灌1h处理;HTK组和FW组在模拟I/R过程中,分别加HTK液和FW液于细胞培养基中进行干预。用全细胞膜片钳技术检测INa的电流强度和门控特性。结果与I/R组和HTK组相比,FW组的INa的峰值电流密度明显降低(-305.9±64.1pA/pFvs-617.2±74.2pA/pF和-547.3±20.8,P<0.05),I-V曲线上移。HTK组较I/R组峰值电流密度降低,但两者没有统计学差异。与I/R组和FW组相比,HTK组的稳态激活曲线和失活曲线左移。各组半激活电压、激活曲线斜率、半失活电压、失活曲线斜率、失活后恢复曲线时间常数均无显著性差异。结论 FW液可抑制乳鼠心肌细胞I/R损伤后的INa通道电流,但不影响快钠通道的门控特性,这有利于减少细胞内钠钙超载,减轻I/R导致的心肌损伤。

Effect of Fuwai polarizing solution on sodium channel in ischemia-reperfusion neonatal rat myocytes

Objective To study the effect of Fuwai polarizing （FW） solution on sodium channel （1Na） in ischemia-reperfusion （I/R） neonatal rat myocytes. Methods Myoeytes were primary cultured for 18-48 h before using in the experiment. Cells were treated with I/R in the I/R group and with FR plus Histidine-tryptophan-ketoglutarat （HTK） solution or FW solution in the HTK and the FW group, respectively. Whole cell patch clamp was used to record the current and gating. Results The peak current density in the FW group decreased significantly than the FR and the HTK group （-305.9±64.1 pA/pF vs -617.2±74.2 pA/pF 和 -547.3±20.8, P （0.05）, the I-V curve of FW group up-shifted. The peak current in the HTK group decreased than the I/R group, however no significant difference was observed. Compared with the I/R and the FW group, the activation and inactivation curves of the HTK group left-shifted. Conclusions FW solution could inhibit the INa current after I/R injury in neonatal rat myocytes without affecting the gating characteristics of the channel. This could help alleviating intraeellular Na＋ and calcium （Ca2＋） overload.