缺血预适应对猫体外循环中心肌细胞膜脂质成分变化的影响

Effect of ischemic preconditioning on changes of membrane phospholipid and cholesterol content in myocardial cells of felines during cardiopulmonary bypass

目的 :研究缺血预适应 (IPC)对猫体外循环 (CPB)中缺血再灌注损伤所致心肌细胞膜总磷脂及胆固醇含量变化的影响。 方法 :建立猫体外循环模型并随机分为 3组 ,每组 2 5只。对照组仅行单纯 CPB,不阻断主动脉 (ACC) ;缺血再灌注组 (IR组 )于 CPB后 4 5 min行 ACC,6 0 m in后使心脏复跳 ,恢复再灌注 4 5 min;IPC组于 ACC前行 IPC(ACC5 min后开放 1 0 m in,重复 3次 ) ,余处理同 IR组。测定 CPB过程中各时间点心肌细胞膜总磷脂及胆固醇含量并计算胆固醇 /磷脂比值 (C/ P)。 结果 :IR组 ACC6 0 m in时心肌细胞膜总磷脂及胆固醇含量较 CPB前明显减少 (P<0 .0 1 ) ,但 C/ P无明显变化 ,再灌注 4 5 min时心肌细胞膜总磷脂及胆固醇含量进一步降低 ,与 ACC6 0 m in相比有显著性意义 (P<0 .0 1 ) ,同时伴有 C/ P升高 ;IPC组ACC6 0 m in时心肌细胞膜总磷脂及胆固醇含量与 CPB前相比无明显降低 ,再灌注 4 5 min时 ,心肌细胞膜总磷脂及胆固醇含量虽明显低于 CPB前水平 (P<0 .0 1 ) ,但显著高于 IR组 (P<0 .0 1 ) ,IPC组 CPB全过程中 C/ P未发生明显变化。 结论 :IPC可通过减少

Objective:To elucidate the influences of ischemic preconditioning(IPC) on the changes of membrane phospholipid and cholesterol content in ischemia and reperfusion(IR) myocardial cells during cardiopulmonary bypass(CPB).Methods: Seventy five felines were randomized into 3 groups: control group( n =25),in which CPB was conducted without aortic cross clamping(ACC); IR group( n =25),with 60 min ACC followed by 45 min reperfusion,and cardioplegia was used during ACC; IPC group( n =25),with protocol was similar to that of IR group except for three cycle 15 min IPC applied before ACC.Myocardium samples were obtained from apex of the left ventricule of feline 45,75,105,120,150 min after onset of CPB,and membrane phospholipid and cholesterol content of myocardial cells were measured.Results: In IR group,phospholipid and cholesterol contents on myocardial cell membrane were significantly declined at the end of ACC period and kept decreasing during reperfusion period.However,the C/P of myocardial cell membrane kept unchanged during ACC period but was markedly elevated during reperfusion period.In IPC group,no elevation of myocardial cell membrane phospholipid and cholesterol content was observed during ACC period,and lower membrane phospholipid and cholesterol contents were found compared to that in IR group during reperfusion period, which were slightly higher than that in control group.C/P of myocardial cell membrane kept unchanged during both ACC and reperfusion periods in IPC group.Conclusion: IPC may be effective in protecting myocardial cells from IR injury by reducing the loss of membrane phospholipid and cholesterol caused by IR during CPB.