磷酸肌酸联合缺血后适应对大鼠心肌缺血/再灌注损伤的保护作用

Phosphocreatine enhances the protective effects of ischemic postconditioning on myocardial ischaemia-reperfusion injury in rats

目的探讨磷酸肌酸后适应联合缺血后适应对大鼠心肌缺血/再灌注损伤的作用。方法取健康、♂、SPF级Wistar大鼠40只,体质量260～290 g。随机分成4组(各组10只):缺血/再灌注组(I/R组)、缺血后适应组(IPost组)、磷酸肌酸后适应组(PCr组)、磷酸肌酸后适应+缺血后适应组(PCr+IPost组),均给予心肌缺血30 min,再灌注120 min处理。再灌注2 h后用比色法测量各组大鼠血清肌酸激酶(CK)、乳酸脱氢酶(LDH)、髓过氧化物酶(MPO)活性;ELISA方法检测血清肿瘤坏死因子-α(TNF-α);Western blot方法检测缺血心肌磷酸化的蛋白激酶B(P-Akt)、Bcl-2蛋白表达;TTC染色测定心肌梗死面积。结果 IPost、PCr组血清CK、LDH、MPO、TNF-α及心肌梗死面积明显低于I/R组,PCr+IPost组较IPost、PCr组各项指标进一步降低;而IPost、PCr组心肌组织P-Akt、Bcl-2蛋白水平明显高于I/R组,PCr+IPost组较IPost、PCr组蛋白水平进一步升高。结论磷酸肌酸后适应联合缺血后适应可以明显减轻大鼠心肌缺血/再灌注损伤,其作用机制可能与共同激活PI-3K/Akt/Bcl-2信号通路及抑制炎症反应有关。

Aim To investigate the combined effect of phosphocreatine（PCr）and ischemic postconditioning（IPost）on myocardial ischemia-reperfusion（I/R）injury in rat model.Methods In anesthetized open-chest Sprague-Dawley rats,the left anterior descending artery（LAD）was occluded for 30 min and reperfused for 120 min.All rats were randomly divided into four groups（n=10 in each group）：I/R group without other interventions,IPost group with 3 cycles of 10s reperfusion and 10 s ischemia,PCr was applied 200 mg·kg-1 through the femoral before reperfusion 5min,PCr＋IPost（PCr was applied and IPost before reperfusion）.Myocardial infarct size（IS） was measured by 2,3,5-Triphenyltetrazolium chloride staining at the end of the experiment;the activities of serum creatine kinase（CK）,lactate dehydrogenase（LDH）,myeloperoxidase（MPO）were measured after 120 min of reperfusion respectively;serum levels of tumor necrosis factor-α（TNF-α）was detected by ELISA;myocardial expression of P-Akt and Bcl-2 was determined by Western blot.Results IS,CK,LDH,MPO,TNF-α were all significantly reduced in IPost and PCr group compared with the I/R group（P0.05）,and these benefical effects were further enhanced in PCr＋IPost group（P0.05）.P-Akt and Bcl-2 were significantly increased in IPost and PCr group compared with the I/R group（P0.05）,and these benefical effects were further enhanced in PCr＋IPost group（P0.05）.Conclusion PCr＋IPost can alleviate myocardial ischemia-reperfusion injury in rat model by activating PI-3K/Akt/Bcl-2 signaling pathway and inhibiting inflammatory response.