预适应和后适应对缺血/再灌注损伤大鼠心肌组织炎症因子的影响

Effect of Ischemic Preconditioning and Ischemic Postconditioning on Inflammatory Factors of Myocardium in Rats with Reperfusion Injury

目的:观察缺血预适应(IPC)、缺血后适应(IPOC)对大鼠心肌组织缺血/再灌注(I/R)损伤后Toll样受体(TLR)及下游炎症因子的影响。方法:SD大鼠60只,通过SPSS软件随机分为假手术组(冠状动脉前降支下置线不结扎,n=15);I/R组(冠状动脉前降支结扎30min,再灌注60min,n=15);IPC组(冠状动脉前降支3次3min/5min的缺血/再灌注循环,然后结扎30min后,再持续灌注60min,n=15);IPOC组(冠状动脉前降支结扎30min,3次10s的缺血/再灌注循环,再持续灌注60min,n=15)。实验结束后测定大鼠血清肌酸激酶同工酶(CK-MB)和肌钙蛋白T(cTNT)水平;氯化硝基四氮唑兰(NBT)染色测定大鼠左室心肌梗死面积;免疫组织化学法测定心肌组织TLR-2、4的表达;酶联免疫吸附法测定心肌组织白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)、单核细胞趋化蛋白-1(MCP-1)和肿瘤坏死因子-α(TNF-α)的含量。结果:与I/R组比较,IPC组、IPOC组大鼠血清CK-MB和cTNT水平显著降低(P<0.01),心肌梗死面积显著减小(P<0.01),心肌组织TLR-2、4表达和炎症因子IL-6、IL-1β、MCP-1、TNF-α含量显著下降(P<0.05,P<0.01);与IPC组比较,IPOC组减小I/R大鼠心肌梗死面积,降低血清CK-MB及心肌组织IL-6等作用和IPC组无显著差异(P>0.05)。结论:IPOC与IPC同样具有减轻心肌I/R损伤程度和缩小心肌梗死范围等作用,抑制TLR-2、4的表达可能是其保护I/R心肌的一个重要途径。

Objective: To investigate the effect of ischemic preconditioning(IPC) and ischemic post conditioning(IPOC) on toll-like receptor(TLR)expression and it's downstream inflammatory factors of myocardium in rats with reperfusion injury.Method: Sixty Sprague-Dawley rats were randomly divided into Sham-operated group(the suture was penetrated around the left anterior descending coronary(LAD) artery,but not tied,n=15),I/R group(30 minutes' occlusion of the LAD,followed by 1 hour' reperfusion,n=15),IPC group(3 cycles of 3minutes'ischemia/5 minutes' reperfusion of the LAD,30 minutes' occlusion followed before 1 hour' reperfusion,n=15),IPOC group(30 minutes' occlusion of the LAD,followed by 3 cycles of 10 seconds' ischemia/10 seconds' reperfusion before 1 hour' reperfusion,n=15).After the process mentioned above,Serum CK-MB and cTnT levels were detected,myocardial infarction size was measured by NBT staining,TLR2 and TLR4 in myocardial tissue were examined by immunohistochemistry method.IL-1β,IL-6,MCP-1 and TNF-α levels of myocardial tissue were examined by ELISA.Results: Compared with I/R group,myocardial enzymes and infarction size decreased significantly in IPC and IPOC group(P<0.01),expression of TLR2,4 and levels of IL-1β,IL-6,MCP-1 and TNF-α in myocardial tissue were significantly lower than those in I/R group(P<0.05,P<0.01).Compared with IPC group,there were no significant differences between IPOC and IPC group with the effect of reducing infarction size and serum CK-MB levels(P>0.05).Conclusion: IPOC can alleviate myocardium I/R injury and reduce infarction size with the same effect of IPC,one of it's possible important pathway is the inhibition of the expression of TLR2,4.