加味温胆汤调控INSR/PI3K/Akt/GLUT4信号通路抗雄性幼鼠营养性肥胖机制研究

Research on Mechanism of Modified Wendan Decoction(加味温胆汤)Anti-Nutritional Obesity in Young Male Rats by Regulating INSR/PI3K/Akt/GLUT4 Signal Pathway

目的通过观察加味温胆汤对雄性营养性肥胖幼鼠INSR/PI3K/Akt/GLUT4信号通路相关指标含量及mRNA表达的影响,探讨该方抗雄性幼鼠营养性肥胖的机制。方法 60只SD雄性幼鼠按体质量随机分为正常对照组、模型对照组、加味温胆汤高、中、低剂量组(8.6、4.3、2.15 g·kg^(-1));采用"高脂乳剂+拌油饲料"喂养复制幼鼠营养性肥胖模型,灌胃给药,连续5周,分离血清和骨骼肌组织,采用酶联免疫法(ELisa)检测血清甘油三酯(TG)、游离脂肪酸(FFA)、总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、低密度脂蛋白胆固醇(LDL-C)、胰岛素(INS)及骨骼肌INS、胰岛素受体(INSR)、葡萄糖转运体4(GLUT4)含量,采用实时荧光定量PCR法(Real-time PCR)检测骨骼肌胰岛素受体底物2(IRS2)、磷脂酰肌醇3激酶(PI3K)、蛋白激酶B2(Akt2)和GLUT4 mRNA表达水平。结果与模型对照组比较,加味温胆汤高剂量组可显著降低幼鼠Lee’s指数、血清TG水平,升高血清HDL-C、骨骼肌GLUT4含量,上调骨骼肌IRS2 mRNA表达水平;加味温胆汤中剂量组可降低幼鼠血清LDL-C水平,升高骨骼肌组织INSR、GLUT4含量,上调骨骼肌IRS2、PI3K、Akt2和GLUT4 mRNA表达;加味温胆汤低剂量组可升高骨骼肌INSR水平,并上调骨骼肌PI3K mRNA的表达水平。以上结果均具有统计学意义(P<0.01或P<0.05)。结论加味温胆汤抗雄性幼鼠营养性肥胖的机制与上调幼鼠骨骼肌INSR及IRS2 mRNA表达水平,激活胰岛素受体后PI3K/Akt/GLUT4信号通路,调节脂肪、葡萄糖等代谢有关,其中高、中剂量组作用突出。

Objective To explore the mechanism of anti-nutritional obesity in young rats by observing the effect of Modified Wendan Decoction(加味温胆汤) on INSR/PI3 K/Akt/GLUT4 signal pathway in young male rats with nutritional obesity. Methods Totally 60 SD young male rats were randomly divided into 5 groups according to their body weight: normal control group, model control group and Modified Wendan Decoction high, medium and low dose groups(8.6,4.3,2.15 g·kg^(-1)). The male nutritional obesity model was built by the daily mixed oil feed and the self-made high fat emulsion free diet in this study. Each group was given continuous administration by gavage for 5 weeks. The serum and skeletal muscle of each group rats were separated. The contents of triglyceride(TG),free fatty acid(FFA),total cholesterol(TC),high-density lipoprotein cholesterol(HDL-C),low-density lipoprotein cholesterol(LDL-C),insulin(INS)in serum and INS,insulin receptor(INSR) and glucose transporter 4(GLUT4)in skeletal muscle were measured by enzyme-linked immunosorbent assay(ELISA) and the expression levels of insulin receptor substrate 2(IRS2),phosphotidylinositol 3-kinase(PI3 K),protein kinase B2(Akt2) and GLUT4 mRNA in skeletal muscle of each group were detected by Real-time quantitative Polymerase Chain Reaction(Real-time PCR). Results Compared with the model control group, the high-dose group of Modified Wendan Decoction can reduce the index of Lee’s and the content of TG in serum, increase the content of HDL-C in serum and the content of GLUT4 in skeletal muscle, up-regulate the expression level of skeletal muscle IRS2 mRNA. The middle dose group can decrease the content of LDL-C in serum and increase the contents of INSR and GLUT4 and up-regulate the expression levels of IRS2,PI3 K,Akt2 and GLUT4 mRNA in skeletal muscle. The low dose group could increase the level of INS and up-regulate the expression of PI3 K mRNA in skeletal muscle. The above results were statistically significant(P<0.01 or P<0.05). Conclusion The mechanism of Modified Wendan Decoction against nutritional obesity in young male rats is related to up-regulating the content of INSR and the expression of IRS2 mRNA in skeletal muscle, activating insulin post-receptor PI3 K/AktGLUT4 signal pathway and regulating the metabolism of lipid and glucose. Both the high and medium dose groups have better effects.