论文部分内容阅读
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 investigate the effect of leucine (Leu) on insulin sensitivity and lipometabolism in skeletal muscle of insulin-resistant rats induced by high fat diet, and to provide basis for exploring the relationship between Leu and insulin resistance and related mechanisms. Methods Skeletal muscle of 4 to 5 d SD suckling rats were cultured in tissue culture and insulin resistance model was induced by palmitic acid (PA). Serum levels of triglyceride (TG), ATP and residual glucose in the culture medium were measured by colorimetric method after 2 mmol / L Leu exposure. The effect of Leu on lipid drop formation in skeletal muscle was observed by oil red O staining Real-time PCR was used to detect mitochondrial DNA (mtDNA), peroxisome proliferators-activated receptor γ-coactivator-1α (PGC-1α), silencing information regulator 1 (silent information regulator 1, SIRT1) expression levels. Results Leu intervention could significantly decrease the concentration of glucose in the supernatant of insulin resistance group induced by high fat diet, decrease the level of TG in skeletal muscle, increase the level of ATP and mtDNA in the tissue, and significantly enhance the mitochondrial regulatory genes SIRT1 and PGC-1α The expression level. Conclusion Leu supplementation may improve insulin resistance in skeletal muscle, which may be related to the mitochondrial function by increasing the expression level of SIRT1 go PGC-1α in skeletal muscle.