Effect of ischemic preconditioning on alterations in regional fluidity of myocardial membrane during cardiopulmonary bypass / 解放军医学杂志

ABSTRACT

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.