运动对高脂饮食诱导非酒精性脂肪肝的治疗作用

目的 观察运动对高脂饮食诱导非酒精性脂肪肝的治疗作用,并初步探讨其相关机制.方法 将30只Wistar大鼠分为对照组及高脂组,分别给予基础饲料和高脂饲料喂养;高脂组大鼠经喂养18周后制成胰岛素抵抗(IR)模型,并进一步细分为静息组和运动组,继续给予高脂饲料喂养,运动组同时进行游泳训练,共持续6周.于实验进行24周后处死各组大鼠,计算肝指数,观察肝脏病理学改变,检测各组大鼠肝脏甘油三酯(TG)含量,同时应用蛋白免疫印迹法检测肝脏组织一磷酸腺苷活化蛋白激酶(AMPK)磷酸化水平.结果 实验进行24周后,与对照组比较,静息组大鼠胰岛素敏感性显著降低,肝脏TG含量、肝指数明显增高,光镜下肝脏出现明显脂肪变性,肝脏内AMPK磷酸化水平降至对照组水平的50.8%;与静息组比较,运动组大鼠胰岛素敏感性明显提高,肝指数及肝脏TG含量均显著降低,光镜下可见肝脏脂肪变性程度明显改善,肝组织内AMPK磷酸化水平亦显著提高.结论 运动干预对高脂饮食诱导的非酒精性脂肪肝具有治疗作用,其机制可能与运动上调肝脏组织中AMPK磷酸化水平,从而改善IR及减少肝脏内TG含量有关.

Abstract：

Objective To observe the effect of exercise on nonalcoholic fatty liver disease (NAFLD) induced by high-fat diet and explore the mechanism.Methods Thirty healthy male rats were randomly divided into a normal control group( NC group) and a high-fat group( HF group), fed with normal chow and high-fat diet, respectively.Eighteen weeks later, the high-fat established as insulin resistance model and group was randomly divided into high-fat diet control group (HC group) and high-fat diet exercise group (HE group).HC group was continually given high-fat diet; HE group accepted swimming training for 6 weeks.After 24 weeks, the insulin sensitivity index (ISI) was calculated.After rats were sacrificed, weight of liver and body were measured to calculate liver mass index.Liver histology was detected by hematoxylin and eosin staining.Hepatic triglyceride content was detected.Phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) level was detected by Western blot technique.Results At the 18th week, compared to NC group, ISI of HF group decreased obviously.It suggested that insulin resistance appeared in HF group.At the 24th week, compared to NC group, ISI of HC group decreased significantly.But hepatic triglycefide content and liver mass index both increased.Pathology observation under light microscope showed obvious liver steatosis in HC group.Phosphorylation of AMPK level in HC group decreased to 50.8% of NC group.Exercise greatly improved the liver mass index, hepatic triglyceride content and ISI as well as liver steatosis compared to HC group.Phosphorylation of AMPK was also elevated to 78.1% of NC group in HE group.However,compared to NC group, liver mass index and hepatic triglyceride content increased simultaneously, while ISI and phosphorylation of AMPK level obviously decreased in HE group.Conclusion Elevated level of phosphorylation of AMPK contributed to improve insulin resistance and decrease the hepatic triglyceride content.Exercise could markedly improve NAFLD induced by high-fat diet through elevating phosphorylation of AMPK in liver.

Therapeutic effect of exercise on nonalcoholic fatty liver disease induced by high-fat diet