缺血后处理对大鼠缺血／再灌注心肌髓过氧化物酶及细胞间粘附分子的影响

目的：研究缺血后处理对大鼠缺血／再灌注心肌髓过氧化物酶（MPO）及可溶性细胞间粘附分子（sICAM）的影响。方法：选择健康SD大鼠48只，随机分为3组：假手术组、缺血再灌注组（对照组）和缺血后处理组。每组16只。制备大鼠心肌缺血再灌注模型。缺血再灌注组．收紧结扎线缺血40min，放松结扎线再灌注240min；缺血后处理组．缺血40min后．再灌注10S．缺血108，连续3个循环，然后再灌注240min；假手术组，开胸后穿线做套环，但不收紧结扎线。再灌注结束后检测血清肌酸激酶（CK）活性、sICAM含量及心肌MPO活性。结果：①血清CK活性：试验后缺血后处理组和缺血再灌注组（对照组）的CK活性明显高于假手术组分别为（736．28±21．72），（987．62±28．58），（256．34±19．34）U／L，P〈0．01]，缺血后处理组的明显低于对照组（P〈0．01）。②心肌MPO活性：缺血后处理组和对照组的均显著高于假手术组（P〈0．01）。缺血后处理组的较对照组显著降低（0．86±0．08）U／G：（1．28±0．26）U／G。P〈0．01]。③血清sICAM含量：缺血后处理组和对照组血清的sICAM含量均显著高于假手术组（P〈0．01）。缺血后处理组的较对照组显著降低（54．28±11．69）ng／ml：（76．62土13．45）ng／ml．P〈0．01]。结论：缺血后处理可减轻缺血再灌注损伤，其机制可能与减轻氧化损伤、抑制白细胞的粘附有关。

Effect of postconditioning on MPO and sICAM in rats with myocardial ischemia reperfusion

Objective.. To study the effect of postconditioning on MPO and sICAM in rats with myocardial ischemia reperfusion. Methods： Totally 48 rats were randomly divided into three groups： Control group （n =16） ： In anesthetized open-chest rats, the left anterior descending （LAD） coronary artery was occluded for 40 rain and reperfused for 4 h, no intervention for reperfusion; Ischemic postconditioning （IP） group （n = 16）： after LAD occlusion 40 rain, three cycles of l0 s reperfusion followed by 10 s LAD re-occlusion were applied during the first minute of reperfusion, then reperfused for 4 h; Sham group （n= 16） ： the surgical procedure was identical to other groups, hut the LAD ligature was not ligated. The serum Creatine kinase （CK）, myeloperoxidase （MPO） activity and sICAM content were measured. Results： Serum CK activity in IP group was lower than that in control group （736.28±21.72） U/L, （987.62±28.58） U/L, P〈0.01]. Both the MPO activity and slCAM content were lower in IP group than those in controlgroup （0.86±0.08） U/g： （1.28±0.26） U/g, （54.28±11.69） ng/ml： （76.62±13.45） ng/ml respectively, P〈0. 011. Conclusion： IP has protective effect on injury induced by I/R in rats. It has the effect decreasing MPO activity and ameliorating neutrophil adhesion and infiltration.