氧化苦参碱对高脂饮食诱导胰岛素抵抗载质蛋白E基因敲除小鼠肝脏三酰甘油代谢酶的影响

摘要

目的 探讨氧化苦参碱对高脂诱导胰岛素抵抗载脂蛋白E基因敲除(ApoE－/－)小鼠肝脏三酰甘油代谢酶的影响. 方法 72 只ApoE－/－小鼠高脂喂养16周,随机分为模型组,氧化苦参碱25 mg/kg 、50 mg/kg 、100 mg/kg组,灌胃8周,C57BL/6J小鼠设为对照组.测定血清生化指标,高胰岛素-正葡萄糖钳夹试验评价胰岛素抵抗,苏木素伊红(HE)染色观察肝脏病理变化,实时荧光定量聚合酶链反应(QRT-PCR)和免疫印迹分析(Western blot)检测肝组织三酰甘油代谢酶基因表达. 结果 氧化苦参碱能不同程度降低小鼠体重、血糖、三酰甘油、胆固醇,减轻肝脏病理变化;氧化苦参碱 25 mg/kg 、50 mg/kg 、100 mg/kg组葡萄糖输注率(18. 5 ± 1. 6 )mU · kg －1· min－1、(20.1 ± 1.8)mU · kg －1· min－1、(21.3 ± 2.3)mU · kg －1· min－1,高于模型组(16.5 ± 1.6)mU·kg －1·min－1(P＜0.05).与模型组比较,氧化苦参碱组肝脏激素敏感性脂肪酶(HSL)、脂肪三酰甘油酶(ATGL) 、过氧化物酶体增殖物激活受体γ(PPARγ)mRNA表达均升高,二酯酰甘油酰基转移酶基因(DGAT1)mRNA表达下降(F＝53.81 、21.06 、23.67 、35.37 ,均 P＜0.05) ,氧化苦参碱50 mg/kg 、100 mg/kg组 HSL 、ATGL 、PPARγ蛋白表达升高,DGAT1 蛋白表达下降(F＝53. 62 、22. 87 、28. 13 、33. 54 ,均 P＜0. 05) . 结论 氧化苦参碱能改善高脂诱导小鼠的胰岛素抵抗,与调节肝脏三酰甘油代谢酶有关.%Objective To investigate the effect of oxymatrine on liver triglyceride metabolism enzymes of apolipoprotein E(ApoE)－/－mice with fat-induced insulin resistance. Methods A total of 72 ApoE－/－mice fed with a high-fat diet for 16 weeks were randomly assigned into a model group ,an oxymatrine 25 mg/kg group ,an oxymatrine 50 mg/kg group ,and an oxymatrine 100 mg/kg group , and oxymatrine was administered p.o.for 8 weeks.C57BL/6J mice were selected to serve as the control group.Serum biochemical parameters were assessed ;Insulin resistance was assessed with the Hyper insulinemic-euglycemic clamp test ;Pathological changes in the liver were visualized by hematoxylin ( HE ) staining ;levels of gene expression of triglyceride metabolism enzymes were examined by real-time polymerase chain reaction ( PCR ) and Western-blotting. Results Administration of oxymatrine reduced body weight ,fasting blood glucose , cholesterol ,and triglyceride to varying degrees and alleviated pathological changes in the liver.Glucose infusion rates were(18.5 ± 1.6)mU · kg －1· min－1,(20.1 ± 1.8)mU · kg －1· min－1,and(21.3 ± 2.3)mU · kg －1· min－1in the oxymatrine 25 ,50 ,and 100 mg/kg groups ,respectively ,and were significantly higher than that in the model group (16.5 ± 1.6)mU · kg －1· min－1(all P ＜ 0.05) .mRNA expression levels of hormone-sensitive lipase(HSL) ,adipose triglyceride lipase(ATGL) ,and peroxisome proliferator-activated receptor γ(PPARγ)were higher in the three oxymatrine groups than in the model group ,while levels of diacylglycerol acyltransferase (DGAT1 ) were lower in the oxymatrine groups(F＝53.81 ,21.06 ,23.67 ,35.37 ;all P＜0.05) ;Levels of HSL ,ATGL ,and PPARγ were higher ,while levels of DGAT1 were lower in the oxymatrine 50 and 100 mg·kg －1groups than in the model group ( F ＝ 53.62 ,22.87 ,28.13 ,33.54 ;all P ＜ 0.05 ). Conclusions Oxidative can mitigate insulin resistance in mice fed with a high fat diet through regulating the expression of liver triglyceride metabolism enzymes.