【作者】 刘锐； 郝丽萍； 李想； 马俊； 刘浩； 杨雪锋；

【Author】 LIU Rui,HAO Li-ping,LI Xiang,MA Jun,LIU Hao,YANG Xue-feng~* (Department of Nutrition and food Health,Tongji Medical College,Hua Zhong University of Science and Technology,Wu Han 430030,China)

【机构】 华中科技大学同济医学院营养与食品卫生学系；

【摘要】 目的:以原代培养的大鼠骨骼肌细胞为研究对象,观察亮氨酸对骨骼肌细胞及渥曼青霉素Wortmannin处理后葡萄糖摄取能力及胰岛素信号通路关键分子AKT表达的影响,从而为探讨亮氨酸与胰岛素抵抗的关系和相关机制提供依据。方法:组织块法培养大鼠原代骨骼肌细胞,不同浓度的亮氨酸(0,0.4,2.0,4.0,8.0mmol/L)作用80min或45min,酶法测定基础状态下和胰岛素刺激下葡萄糖摄取能力,确定亮氨酸作用的最佳浓度和作用时间;在此基础上,应用PI-3K抑制剂Wortmannin作用30min,测定葡萄糖摄取能力,Western blot检测AKT及磷酸化AKT表达水平。结果:无论是基础状态还是胰岛素刺激下,2mmol/L亮氨酸作用45min骨骼肌细胞葡萄糖摄取能力达最大;2mmol/L亮氨酸干预可改善wortmannin对胰岛素刺激下骨骼肌细胞葡萄糖摄取的抑制作用,显著增强胰岛素信号传导关键分子pSer473 AKT的表达。结论:亮氨酸可改善骨骼肌细胞胰岛素抵抗。这种作用不完全依赖于PI-3K胰岛素信号传导通路,并且可能与其增强AKT磷酸化水平有关。更多还原

【Abstract】 Objective To examine the effects of leucine on glucose uptake and AKT expression in normal and Wortmannin treated primary culture skeletal muscle cells of rats.Methods Exposure to different doses of leucine(0,0.4,2,4,8mmol/L) with or without insulin(100nmol/L) for 80min or 45min,2-deoxyglucose uptake of skeletal muscle cells was determined by a nonradioisotope enzymatic microplate assay.Cells were pretreated with or without Wortmannin for 30min,then incubated with 2mmol/L leucine or/and insulin for 45min.Western blot was used to detect AKT and phosphoAKT(Ser473) expression.Results Glucose uptake of primary culture skeletal muscle cell enhanced when exposure to 2mmol/L leucine for 45min.Leucine allows insulin to activate AKT and improve glucose uptake when PI-3K was blocked.Conclusion Leucine can promote glucose uptake in normal and Wortmannin-treated skeletal muscle cells.The underlying mechanism is partly independent of PI-3K insulin signaling and associated with the phosphorlation of AKT.更多还原