缺血预适应对体外循环中心肌细胞膜蛋白生物物理特性的影响  

Effects of ischemic preconditioning on biophysical property of myocardial cell membrane proteins in felines during cardiopulmonary bypass

作　　者：王志农[1] 何斌[1] 曾志勇[1] 张波[1] 徐志云[1] 黄盛东[1] 张宝仁[1] 

机构地区：[1]第二军医大学长海医院胸心外科,解放军胸心外科研究所上海200433

出　　处：《第二军医大学学报》2004年第4期359-362,共4页Academic Journal of Second Military Medical University

基　　金：上海市曙光计划资助项目 ( 0 2 SG3 0 ) ;上海市青年科技启明星计划资助项目 ( 0 0 QB14 0 5 3 )

摘　　要：目的 :观察缺血预适应 (IPC)对体外循环 (CPB)中缺血再灌注心肌细胞膜蛋白生物物理特性变化的影响。 方法 :建立猫 CPB模型并随机分成 3组 :对照组 (n=30 )仅作单纯的并行 CPB;缺血再灌注组 (IR组 ,n=30 )阻断主动脉 (ACC) 6 0 m in,恢复心脏血液再灌注 90 min;IPC组 (n=30 )于 ACC前进行 IPC(ACC5 m in后开放 1 0 min,并重复 3次 ) ,余同 IR组。应用电子顺磁共振波谱测定心肌细胞膜蛋白巯基强 /弱固定相峰高比值 (h S/ h W)和膜蛋白旋转相关时间 (τc)的动态变化 ,同时直接测定心肌组织中氧自由基水平。 结果 :对照组 h S/ h W和 τc 以及心肌组织中氧自由基水平在 CPB前后无明显变化 ;IR组 h S/ h W和 τc在 ACC30 min明显升高 ,并于再灌注期间进一步上升 (P<0 .0 1 ) ,同时伴有心肌中氧自由基水平的升高 (P<0 .0 5 ) ;IPC组再灌注期间 h S/ h W 和 τc虽较对照组有所升高 ,但均明显低于 IR组 (P<0 .0 5 ) ,而且 IPC组氧自由基水平在再灌注期 90 min基本恢复 CPB前水平。直线回归分析显示 h S/ h W 和 τc均与心肌组织中氧自由基含量的水平呈显著正相关 ,相关系数分别为0 .71 2和 0 .6 6 1 (P<0 .0 5 )。结论 :IPC能减少心肌再灌注期间氧自由基的产生 ,有利于 CPB中缺血再灌注心肌细胞膜蛋白生物物理?Objective:To elucidate the effects of ischemic preconditioning (IPC) on the biophysical property of myocardial cell membrane proteins in ischemia and reperfusion (IR) injury during cardiopulmonary bypass (CPB). Methods: Ninety felines were randomized into 3 groups: control group ( n =30), in which CPB was conducted without aortic cross clamping (ACC); IR group ( n =30), with 60 min ACC followed by 90 min reperfusion, and cardioplegia was used during ACC; IPC group ( n =30), with protocol similar to that of IR group except for three cycle 15 min IPC applied before ACC. The electron paramagnetic resonance (EPR) was used to characterize the protein conformation and movement described by the ratio of the strong solidity and weak solidity (h S/h W) and rotational correlation time (τ c) of membrane proteins] of spin labelled sulfhydryl ( SH) group in myocytes membrane. The level of the myocardial oxygen free radicals was directly determined by electron spin resonance concomitantly. Results: Both the h S/h W and τ c of myocardial cell membrane proteins in IR group were significantly increased during 60 min cardiac arrest and became more pronounced during 90 min myocardial reperfusion period, which were accompanied simultaneously by elevation of oxygen free radicals in myocardium. However, the above changes were alleviated obviously in IPC group compared to those of IR group, and the changes were not remarkable in the control group. Moreover, there were significant correlations between h S/h W and oxygen free radicals levels in myocardium as well as between τ c and oxygen free radicals levels with the correlation coefficient being 0.712 and 0.661, respectively ( P <0.05). Conclusion: Myocardial cell membrane proteins conformation and movement of felines receiving ACC during CPB are jeopardized by oxygen free radicals produced during myocardial ischemia and reperfusion,and IPC can alleviate this injury.

关 键 词：缺血预适应 体外循环 心肌细胞 膜蛋白 生物物理特性 

分 类 号：R654.1[医药卫生—外科学]