缺血预处理对体外循环心肌组织磷酯酶A_2及ATPase活性的影响

Effect of Ischemic Preconditioning on Activities of Phospholipase A_2 and ATPase in Myocardial Cells during Cardiopulmonary Bypass

目的观察缺血预处理(IPC)对体外循环中缺血再灌注心肌组织磷酯酶A2(PLA2)和ATPase活性的影响,评价其对心肌的保护作用,并初步探讨其作用机制。方法90只家猫制备体外循环模型,将随机均分3组:单纯体外循环(CPB)组、主动脉阻断组和IPC组。分别测定体外循环时心肌组织PLA2及Na+K+ATPase、Ca2+Mg2+ATPase、Ca2+ATPase的活性,比较各组心肌PLA2及各ATPase活性的变化。结果IPC组可明显减轻CPB时缺血再灌注导致的PLA2活性升高和ATPase活性下降。结论IPC可能通过减轻缺血再灌注期间的Ca2+超载及抑制细胞膜磷脂水解而发挥其心肌保护作用。

Objective To elucidate the influences of ischemic preconditioning（IPC） on activity of phospholipase A2 and ATPase of ischemia/reperfusion myocardial cell during cardiopulmonary bypass （CPB）. Methods Ninety felines were randomized into there groups： group A（n=30）, in which CPB was conducted without aortic cross-clamping（ACC） ; group B（n=30）, with 60 min ACC followed by 90 min reperfusion, and cardioplegia used during period of ACC; group C（n= 30）, with protocol similar to that of group B except for three-round （5 min block and 10 min open blood flow） 15 min IPC applied before ACC. Activities of PLA2 and Na^＋-K^＋-ATPase, Ca^2＋-Mg^2＋-ATPase and Ca^2＋-ATPase of myocardial cells were simultaneously measured during ACC and reperfusion periods. Results IPC significafitly alleviated the upregulated activity of PLA2 and the inhibited activities of Na^＋-K^＋-ATPase, Ca^2＋-Mg^2＋-AT Pase and Ca^2＋-ATPase of myocardium during periods of ischemia and reperfusion. Conclusion IPC can protect myocardial cells from ischemia and reperfusion injury which may due to alleviation of Ca^2＋ overload and hydrolysis of membrane phospholipid by regulating the activities of PLA2 and the ATPases of myocardium.