中文摘要：

目的探讨哺乳类动物雷帕霉素靶蛋白（mTOR）信号转导通路在缺血后处理（I-postC）减轻大鼠骨骼肌缺血再灌注（I/R）损伤中的表达和意义。方法48只雄性健康Wistar大鼠,无创动脉夹夹闭右侧股动脉4h,松夹再灌注12h或24h建立大鼠右后肢I/R损伤模型,随机分为I/R组（n=16）、缺血预处理（IPC）组（5min缺血/5min再灌,3个循环,n=16）及缺血后处理（I-postC）组（1min再灌/1min缺血,3个循环,n=16）。分别于再灌注后12h、24h取标本。观察骨骼肌组织形态学、湿/干重比、丙二醛（MDA）及髓过氧化物酶（MPO）的变化,Western blot和免疫组织化学方法检测mTOR的表达。结果I-postC和IPC组的骨骼肌水肿明显减轻,MDA和MPO指标亦明显降低,与I/R组比较差异显著（P〈0.05）。I-postC组和IPC组之间无显著差异（P〉0.05）。I-postC和IPC组mTOR蛋白产物表达显著增加,与I/R组比较差异显著（P〈0.05）。结论I-postC减轻大鼠后肢骨骼肌I/R损伤,与缺血预处理可能存在共同的作用机制,及通过激活mTOR信号转导通路发挥作用。

英文摘要：

Objective To study the expression of mammalian target of rapamycin（mTOR）in ischemic postconditioning（I-postC）-induced attenuation of ischemia/reperfusion （I/R）injury in rat skeletal muscle. Methods A total of 48 healthy male Wistar rats were randomly divided into 3 groups （n =16 each group）：I/R group （4-hour ischemia followed by 12or 24-hour reperfusion）,ischemic preconditioning （IPC）group（3 cycles of 5-minute ischemia followed by 5-minute reperfusion）,and I-postC group（3 cycles of 1-minute reperfusion followed by l-minute ischemia）. The rat model of I/R injury in right hind limb model was established by clamping the right femoral artery. The changes in the morphology,wet-to-dry weight ratio（W/D）,malondialdehyde（MDA）,and myeloperoxidase（MPO）in skeletal muscle were compared. The expression of mTOR was detected by Western blot and immunohistochemistry. Results In I-postC and IPC groups,the skeletal muscle edema was less severe,the levels of MDA and MPO significantly decreased,and the expression of mTOR significantly increased,compared with I/R group （all P 0.05）. There was no significant difference between I-postC and IPC groups. Conclusion IpostC may attenuate I/R injury in rat hind limbs by activating mTOR signal pathway,which is similar to the mechanism of IPC.