缺血预适应对缺血-再灌注心肌细胞的保护作用

目的观察缺血预处理（IPC）对心肺转流（CPB）中缺血-再灌注心肌损伤及心功能恢复的影响。方法将72只健康家猫随机均分为：单纯CPB组、缺血-再灌注组和IPC组。在猫CPB模型的基础上，测定猫心肌丙二醛（MDA）含量、血清乳酸脱氢酶（LDH）水平和心肌组织磷脂酶A2（PLA2）活性的变化，观察术中心功能的变化。结果IPC组CPB中的血清LDH浓度、心肌MDA含量和心肌组织PLA2活性均明显低于缺血-再灌注组，心脏复跳后各心功能指标的恢复明显优于缺血-再灌注组。结论IPC可减轻CPB中缺血-再灌注心肌细胞的损伤，有利于术后早期心功能的恢复。

Protective effect of ischemic preconditioning on ischemia-reperfusion myocardium

Objective To elucidate the effect of ischemic preconditioning(IPC)on ischemia-reperfusion(I-R) injury of the myocardium. Methods Seventy-two felines were randomized into three groups with 24 cats each.Cardiopulmanary bypass(CPB) was conducted without aortic cross-clamping (ACC) in group C,with 60 min ACC followed by 90 min reperfusion and cardioplegia during period of ACC in group I-R,and with protocol similar to that in group I-R except for three-round 15 min IPC applied before ACC in group IPC. Data about cardial functoin was recorded during CPB. Serum lactate dehydrogenase(LDH)level and malondialdehyde (MDA)content of the myocardium were assayed before and at the end of CPB. The activity of PLA2 of the myocardium was measured at 45, 75, 105, 120 and 135 min after the beginning of CPB.Results Serum LDH level, MDA and PLA2 content of the myocardium were significantly lower in group IPC than those in group I-R at the end of CPB.The recovery of cardiac function in IPC group after reperfusion seemed significantly faster than that in I-R group. Conclusion IPC can protect myocardial cells from ischemia and reperfusion injury.