摘要目的:探讨雷帕霉素预处理对Sprague Dawley(SD)大鼠肝脏缺血再灌注损伤(HIRI)的影响及可能机制。方法:48只无特定病原体雄性SD大鼠体质量180～200 g，鼠龄4～8周，随机分为3组，各16只。雷帕霉素组术前每天腹腔注射雷帕霉素，连续3 d，模型组及假手术组注射生理盐水。雷帕霉素组和模型组制备HIRI模型。术后2、24 h每组随机取8只大鼠，留取血清检测丙氨酸氨基转移酶(ALT)、总胆红素、乳酸脱氢酶；留取肝组织行HE染色，酶联免疫吸附试验检测超氧化物歧化酶(SOD)、谷胱甘肽、己糖激酶2、磷酸果糖激酶1(PFK1)、三磷酸腺苷。聚合酶链反应和蛋白质电泳检测哺乳动物雷帕霉素靶蛋白(mTOR)、核糖体蛋白S6激酶1(S6K1)、蛋白激酶B及其磷酸化水平。结果:术后2 h，模型组血清ALT(150.9±18.7)U/L、总胆红素(5.15±0.69)μmol/L、乳酸脱氢酶(9 547±365)U/L，均高于假手术组(42.4±10.7)U/L、(2.48±0.24)μmol/L、(4 424±376)U/L和雷帕霉素组(87.7±11.2)U/L、(3.09±0.12)μmol/L、(8 268±264)U/L，差异均有统计学意义(均 P<0.05)。HE染色和血清检测结果术后2、24 h模型组肝组织和功能损伤严重，雷帕霉素组损伤减轻。术后2 h和24 h模型组SOD、谷胱甘肽、己糖激酶2、PFK1、三磷酸腺苷低于假手术组和雷帕霉素组，差异均有统计学意义(均 P<0.05)。术后2 h和24 h模型组mTOR、S6K1及其磷酸化相对表达水平高于假手术组和雷帕霉素组，蛋白激酶B及磷酸化蛋白激酶B相对表达低于假手术组和雷帕霉素组，差异均有统计学意义(均 P<0.05)。 结论:雷帕霉素通过抑制mTOR信号通路，上调磷酸化蛋白激酶B，改善糖代谢，降低氧化应激，减轻大鼠HIRI。

abstractsObjective:To investigate the effect of rapamycin on hepatic ischemia-reperfusion injury (HIRI) in Sprague Dawley (SD) rats and its underlying mechanism.Methods:Forty-eight specific pathogen-free SD male rats with the body weight of 180-200 g and the age of 4-8 weeks were randomly divided into 3 groups, 16 rats each group. In the rapamycin group, the rats were injected with rapamycin intraperitoneally everyday lasting for 3 days before the surgery, and in the model group and the sham group, the rats were injected with normal saline intraperitoneally. The HIRI model was performed in the rapamycin group and the model group. Serum of 8 rats was randomly harvested from each group at 2 h and 24 h after the surgery and was used to detect level of alanine aminotransferase(ALT), total bilirubin, and lactate dehydrogenase. At the meantime, liver tissues were collected for HE staining, and enzyme-linked immunosorbent assay of superoxide dismutase(SOD), glutathione, hexokinase 2, phosphofructokinase 1(PFK1), and adenosine triphosphate. Polymerase chain reaction and Western blots were used to determine the levels of mammalian target of rapamycin(mTOR), ribosomal protein S6 kinase 1(S6K1), and protein kinase B and their phosphorylation levels respectively.Results:Two hours post the surgery, the serum level of ALT(150.9±18.7) U/L, total bilirubin(5.15±0.69) μmol/L, and lactate dehydrogenase(9 547±365) U/L were higher in the model group than sham group (42.4±10.7) U/L, (2.48±0.24) μmol/L, (4 424±376) U/L and rapamycin group (87.7±11.2) U/L, (3.09±0.12) μmol/L, (8 268±264) U/L, and all differences were statistically significant (all P<0.05). HE staining and serum assay showed that the lesion of liver tissuesand of liver function were damaged in the model group, and mitigated in the rapamycin group at 2h and 24h after the surgery. At 2h and 24h after the surgery, liver SOD, glutathione, hexokinase 2, PFK1, and adenosine triphosphate in the model group were lower than those in the sham group and the rapamycin group, and all differences were statistically significant (all P<0.05). The relative levels of mTOR, S6K1, and their phosphorylation level in the model group were higher than those in the sham group and the rapamycin group at 2 h and 24 h after the surgery, but the relative levels of protein kinase B and phosphorylated protein kinase B were lower than those in the sham group and the rapamycin group, and all differences were statistically significant (all P<0.05). Conclusions:Rapamycin improves glucose metabolism and reduces oxidative stress via upregulating the phosphorylated protein kinase B through inhibition of mTOR signaling pathway, thus alleviates HIRI in rats.