亮氨酸对胰岛素抵抗大鼠骨骼肌胰岛素敏感性的影响及可能机制  

EFFECTS OF LEUCINE ON INSULIN SENSITIVITY OF SKELETAL MUSCLE IN RATS WITH INSULIN RESISTANCE AND ITS POSSIBLE MECHANISM

作　　者：刘锐[1] 章顺悦[1] 王静 马丹[1] 郭怀兰[1] 

机构地区：[1]湖北医药学院基础医学院预防教研室,十堰442000

出　　处：《营养学报》2014年第4期341-345,共5页Acta Nutrimenta Sinica

基　　金：湖北医药学院研究生科研启动金(No.2011QD2R-1-6)

摘　　要：目的 观察亮氨酸（leucine,Leu）对高脂诱导的胰岛素抵抗大鼠骨骼肌胰岛素敏感性及脂肪代谢的影响,从而为探讨Leu与胰岛素抵抗的关系和相关机制提供依据。方法 取4-5d SD乳鼠的骨骼肌进行组织块培养,通过棕榈酸（palmitic acid,PA）诱导建立胰岛素抵抗模型。2 mmol/L Leu干预24h,比色法检测骨骼肌组织中甘油三酯（triglyceride,TG）含量、ATP水平和培养液中剩余葡萄糖浓度,油红O染色观察Leu对骨骼肌脂滴形成的影响;实时荧光定量PCR检测线粒体DNA含量（mitochondrial DNA,mtDNA）、过氧化物酶体增殖物激活受体协同激活子（peroxisome proliferators-activated receptorγ-coactivator-1α,PGC-1α）、沉默信息调节因子1（silent information regulator 1,SIRT1）表达水平。结果 Leu干预可显著降低高脂诱导的胰岛素抵抗组上清液中葡萄糖浓度,降低其骨骼肌内的TG水平,增加组织内的ATP水平及mtDNA含量,显著增强线粒体调节基因SIRT1和PGC-1α的表达水平。结论 Leu补充可改善骨骼肌胰岛素抵抗,这种作用可能与其通过增加骨骼肌SIRT1 go PGC-lα的表达水平,调节其线粒体的功能有关。Objective To examine the effects of leucine （Leu） on insulin sensitivity and fat metabolism of rat skeletal muscle with insulin resistance and explore its possible mechanism. Methods Isolated rat soleum muscle was incubated with 0.5mmol/L palmitic acid （PA） for 24h to extablish insulin resistance model. When insulin resistance model was extablished, skeletal muscle was incubated with or without 2mmol/L Leu for 24h. Then, triglyceride （TG）, mtDNA （mitochondrial DNA） and ATP content of the skeletal muscle and the glucose concentration of cultured media were determined. The expressions of peroxisome proliferators-activated receptor γ-coactivator-1α（PGC-1α） and silent information regulator 1 （SIRT1） were detected by real-time polymerase chain reaction （RT-PCR）. Results Residual glucose concentration of cultured media was decreased significantly after Leu was added. The content of mtDNA, ATP level and expressions of PGC-1αand SIRT1 were increased in Leu intervention group than those in insulin resistance group. Conclusion Leu supplementation can improve insulin sensitivity of skeletal muscle in insulin resistance rats. The up-regulation of SIRT1, PGC-1α and regulation of the function of mitochondria may be involved in the mechanism.

关 键 词：亮氨酸 脂肪代谢 线粒体 SIRT1 

分 类 号：R587.1[医药卫生—内分泌]