缺血预处理对体外循环中心肌细胞膜区域流动性变化影响的实验研究

目的 观察缺血预处理(IPC)对体外循环(CPB)中心肌细胞膜流动性变化的影响，评价IPC的心肌保护作用。方法 将75只健康家猫随机均分为3组：并行循环组(CPB组)、单纯缺血再灌注组(IR组)和IPC组。应用自旋标记-电子自旋共振技术测定心肌细胞膜的区域流动性。结果 CPB组体外循环过程中心肌细胞膜区域流动性无明显变化，IR组主动脉阻断(ACC)期间细胞膜区域流动性明显降低且于再灌注期间进一步下降，IPC组ACC及再灌注期间细胞膜区域流动性虽较CPB组有所下降但明显高于珉组。结论 IPC能够通过维持心肌细胞膜脂质的流动性，对体外循环中的缺血再灌注心肌产生良好的保护作用。

Effect of ischemic preconditioning on alterations in regional fluidity of myocardial membrane during cardiopulmonary bypass

Objective To elucidate the effect of ischemic preconditioning(IPC)on regional fluidity of myocardial cell membrane during cardiopulmonary bypass (CPB). Methods Seventy-five felines were randomized into three groups: Group A (CPB group,n =25),in which CPB was conducted without aortic cross-clamping (ACC);Group B (IR group,n =25),with 60min ACC followed by 60min reperfusion,and cardioplegia used during period of ACC;Group C (IPC group,n =25),with protocol similar to that of group B except for three-cycle IPC applied before ACC. Electron spin resonance (ESR) technique was employed to monitor membrane regional fluidity of cardiomyocyte during CPB in all groups. Results Regional fluidity of myocardial cell membrane kept unchanged in CPB group and markedly decreased during ACC and reperfusion periods in IR group. Though the regional fluidity of myocardial cell membrane during ACC and reperfusion periods in IPC group was slightly decreased compared to CPB group,it was significantly higher than that in IR group. Conlusion IPC can protect myocardial cells from ischemia and reperfusion injury by maintaining the fluidity of myocardial membrane during CPB.