西罗莫司对大鼠烧伤后IRS-1 Ser^(307)磷酸化和胰岛素抵抗的作用  

Effects of sirolimus on IRS-1 phosphoSer^(307) and insulin resistance in burned rats

作　　者：陈新龙[1] 夏照帆[1] 韦多[1] 田建广[1] 郇京宁[1] 路卫[1] 唐洪泰[1] 朱世辉[1] 

机构地区：[1]第二军医大学长海医院烧伤科,上海200433

出　　处：《第二军医大学学报》2004年第10期1055-1057,共3页Academic Journal of Second Military Medical University

基　　金：国家自然科学基金 ( 3 0 2 713 40 ) ;国家重点基础研究规划 ("973"计划 )课题 ( G19990 5 43 0 9) ;国家高新技术发展规划("863"计划 )课题 ( 2 0 0 1AA2 160 4)

摘　　要：目的 :探讨西罗莫司对大鼠烧伤后胰岛素受体底物 1丝氨酸 30 7(IRS- 1Ser30 7)磷酸化和胰岛素抵抗的作用。方法 :6周龄 SD大鼠 (体质量 16 0～ 170 g)随机分为假烫伤组 (n=8)、烫伤组 (n=8)和烫伤 +西罗莫司组 (n=8)。烫伤组和烫伤 +西罗莫司组大鼠制成烫伤面积为 30 %的 度烫伤模型 ,伤后第 4天禁食 5 h后的大鼠腹腔注射西罗莫司 (0 .4 mg/ kg) 2 h后 ,进行正常血糖高胰岛素葡萄糖钳夹技术实验 ,实验后颈动脉放血处死 ,立即采集肌肉和脂肪标本 ,采用免疫沉淀和免疫印迹方法分析 IRS- 1及其磷酸化丝氨酸 30 7和酪氨酸活性的变化 ,通过免疫组化观察各组肌肉组织中磷酸化哺乳类西罗莫司靶点激酶(m TOR)表达的差异。结果 :正常血糖高胰岛素葡萄糖钳夹技术实验中假烫伤组、烫伤组和烫伤 +西罗莫司组 10 %葡萄糖输注率分别为 (12 .33± 0 .4 2 )、(6 .6 1± 0 .2 7)和 (10 .35± 0 .6 3) m g/ (kg· m in) ,烫伤组和其他 2组比较差异具有统计学意义(P<0 .0 1)。烫伤大鼠肌肉和脂肪组织中 IRS- 1Ser30 7活性较假烫伤组明显升高 (P<0 .0 5 ) ,而 IRS- 1磷酸化酪氨酸活性较假烫伤组明显降低 (P<0 .0 5 )。西罗莫司明显降低烫伤大鼠 IRS- 1Ser30 7活性而明显增加 IRS- 1磷酸化酪氨酸活性 (P<0 .0 5 )。免疫组化?Objective:To investigate the effects of sirolimus on IRS-1 phospho-Ser 307 and insulin resistance after burn in rats. Methods: Twenty-four Sprague-Dawley rats were randomized into control(sham burn trauma),burn(30%TBSA full thickness burn injury) and burn+sirolimus groups(n=8). Euglycemic-hyperinsulinemic glucose clamp was performed 4 d after burn. Sirolimus (0.4 mg/kg) was injected intraperitoneally 2 h before euglycemic-hyperinsulinemic glucose clamps. PhosphoSerine 307 ,phosphotyrosine of IRS-1 and phospho-mTOR in muscles and fat tissues were determined by immunoprecipitation and Western blot analysis or immunohistochemistry. Results: The infused rates of total 10% glucose (GIR, mg/kg·min) in control,burn and burn+sirolimus groups were 12.33±0.42,6.61±0.27 and 10.35±0.63,respectively (P<0.01). The level of IRS-1 Serine 307 phosphorylation in both muscle and fat tissues in vivo increased significantly,while insulin-induced tyrosine phosphorylation of IRS-1 decreased markedly after burn. Sirolimus inhibited the activation of mTOR,reduced Serine 307 phosphorylation,elevated tyrosine phosphorylation and partly prevented the decrease of GIR after burn. Conclusion: Sirolimus inhibits the activation of mTOR,decreases the level of IRS-1 phosphoserine 307 , and, at least partly,ameliorates insulin resistance after burn.

关 键 词：烧伤 胰岛素抵抗 胰岛素受体底物1 丝氨酸307 磷酸化 

分 类 号：R644[医药卫生—外科学]