心肌缺血再灌注损伤对L-型钙通道自抑制功能的影响  

Effect on L-type calcium channel autoinhibition during myocardial ischemia-reperfusion injury

作　　者：夏冰 李心茹 席宏[2] 陈剑楠 杨玲玉 李学文[1] 岳志杰 Xia Bing;Li Xinru;Xi Hong;Chen Jiannan;Yang Lingyu;Li Xuewen;Yue Zhijie(Department of cardiovascular medicine,Third Hospital of Shanxi Medical University,Shanxi Bethune Hospital,Shanxi Academy of Medical Sciences,Tongji Shanxi Hospital,Taiyuan 030032,China;不详)

机构地区：[1]山西医科大学第三医院心血管内科(山西白求恩医院山西医学科学院同济山西医院),太原030032 [2]山西医科大学第三医院麻醉科(山西白求恩医院山西医学科学院同济山西医院),太原030032

出　　处：《中国循证心血管医学杂志》2024年第5期586-592,共7页Chinese Journal of Evidence-Based Cardiovascular Medicine

基　　金：山西白求恩医院人才引进科研启动金项目资助(2022RC08)。

摘　　要：目的探究心肌缺血再灌注(I/R)损伤对L-型钙通道(L-VDCC)自抑制功能的影响及机制。方法采用大鼠离体心脏灌流的方法构建I/R模型,BL-420N生物信号采集与分析系统监测I/R后心脏功能的变化;用CoCl2对急性分离的大鼠心肌细胞造成缺氧损伤,构建细胞I/R模型,并用膜片钳、Co-IP及Western Blot检测L-VDCC的功能变化。结果与缺血0 min组和缺血30 min组相比,缺血60 min组复灌后心脏收缩力降低,心肌电活动减弱;缺氧6 h组和缺氧12 h组相比于缺氧0 h组细胞L-VDCC电流-电压(I-V)曲线峰值增大,稳态激活曲线左移,通道半激活电压(V1/2)增大,稳态激活曲线斜率因子Ka值降低,细胞死亡率增加;Cav1.2结合DCT及CaM的量减少,差异均有统计学意义(P<0.05);PKA、PKG等外源性调节蛋白表达水平无明显变化。结论心肌I/R损伤可引起心肌细胞L-VDCC自抑制功能减弱,Ca2+内流增加,引起细胞钙超载,促进心肌细胞死亡。Objective To investigate the effect of myocardial ischemia-reperfusion(I/R)injury on the autoinhibition function of L-type calcium channels(L-VDCC)and its mechanism.Methods Isolated rat hearts were perfused to establish I/R model.The changes of cardiac function after I/R were monitored by BL-420 N biological signal acquisition and analysis system.CoCl2 was used to cause hypoxia damage in acutely isolated rat cardiomyocytes to construct a cell I/R model.The function of L-VDCC was detected by patch clamp technique,Co-IP and Western Blot analysis.Results Compared with the ischemia 0 min group and ischemia 30 min group,the ischemia 60 min group showed reduced cardiac contractility and weakened myocardial electrical activity after reperfusion.Compared with the hypoxia 0 h group,the peak of the current-voltage(I-V)curve of L-VDCC in the hypoxia 6 h and hypoxia 12 h groups increased,the steady-state activation curve shifted left,the half-activation voltage(V1/2)increased,the slope factor Ka of the steady-state activation curve decreased,and cell death rate increased;the amount of Cav1.2 binding to DCT and CaM decreased,with all differences being statistically significant(P<0.05);there were no significant changes in the expression levels of exogenous regulatory proteins such as PKA and PKG.Conclusion Myocardial I/R injury can weaken the autoinhibition function of myocardial cell L-VDCC,increase Ca2+inflow,cause cell calcium overload,and promote myocardial cell death.

关 键 词：缺血再灌注损伤 钙超载 L型钙通道 自抑制功能 心肌 

分 类 号：R542.2[医药卫生—心血管疾病]