非去极化停搏液对缺血再灌注心肌细胞L-型钙通道的影响

目的探讨非去极化停搏液（non-depolarizing solution，NDP）对缺血再灌注心肌细胞L-型钙通道（ICa-L）的影响。方法实验分为对照（Con）组、缺血再灌注（I／R）组和非去极化停搏液（NDP）组。选择培养18-48h的sD乳鼠心肌细胞用于实验。Con组细胞不经过缺血再灌注处理；VR组细胞经模拟缺血缺氧3h、再灌注1h处理；NDP组在模拟I／R过程中，加NDP液于细胞培养基中进行干预。用全细胞膜片钳技术检测ICa-L的电流强度和门控特性。结果与对照组相比，I／R组ICa-L的峰值电流密度明显降低（-9．0±3．8）pA／pFvs（-15．1±8．8）pA／pF，P〈0．05]，电流-电压曲线（I-V曲线）上移，翻转电位绝对值减小，稳态激活曲线和失活曲线左移，恢复曲线右移。与I/R组相比，NDP组ICa-L的峰值电流密度升高（-11．4±6．7）pA／pFvs（-9．0±3．8）pA／pF，P〈0．05]，I-V曲线下移，翻转电位绝对值增大，稳态激活曲线和失活曲线右移，恢复曲线左移。结论NDP液可减轻心肌细胞I／R损伤对ICa-L通道的抑制作用和门控特性的改变，有利于保护心肌收缩和舒张功能、减少心律失常的发生。

Effect of NDP solution on L-type calcium channel in ischemia-reperfusion neonatal rat myocytes

Objective To study the effect of nondepolarizing(NDP) cardiac preservation solution on L-type calcium channel(ICa-L) in ischemia-reperfusion(I/R) neonatal rat myocytes.Methods Cardiomyocytes were primary cultured for 18-48 h before using in the experiment.Cells were treated without I/R in the Con group,with I/R in the I/R group and with I/R plus NDP solution in the NDP group.Whole cell patch clamp was used to record the current and gating.Results The peak current density in the I/R group decreased significantly than the Con group(-9.0±3.8 pA/pF vs-15.1±8.8 pA/pF,P<0.05).Compared with the Con group,the I-V curve of the I/R group up-shifted,activation curve and inactivation curve left-shifted and recovery curve right-shifted.Compared with the I/R group,the peak current density in the NDP group increased(-11.4±6.7 pA/pF vs-9.0±3.8 pA/pF,P<0.05).The I-V curve of the I/R group down-shifted,activation curve and inactivation curve right-shifted and the recovery curve left-shifted compared with the I/R group.Conclusion NDP solution could alleviate the effect of current inhibition and gating alteration induced by I/R injury in neonatal rat myocytes,which is beneficial to prevent arrhythmias and protect the cardiac contraction and dilatation.