腺苷酸活化蛋白激酶与LKB1在肥胖大鼠脂肪组织中的表达及其对糖脂代谢的影响

The expressions of AMP-activated protein kinase and LKB1 in adipose tissues in obese rats and their impact on glucose and lipid metabolism

目的:探讨腺苷酸活化蛋白激酶(AMP-activated protein kinase,AMPK)与LKB1在肥胖大鼠脂肪组织的表达及其对糖脂代谢的影响。方法:将30只6周龄雄性S-D大鼠随机分为普通饮食组(NC组)和高脂饮食组(HF组),各15只,分别予普通饲料喂养和高脂饲料喂养。喂养16周后,HF组大鼠体重高于NC组20%者为成功建立模型。所有大鼠过夜禁食后,麻醉状态下测量体重(BW),取静脉血测定血清游离脂肪酸(FFA)、甘油三酯(TG)、总胆固醇(TCH)、空腹血糖(FPG)、空腹胰岛素(FINS)。处死大鼠后,采用Western blot法测定各组大鼠骨骼肌组织中AMPKα、磷酸化AMPK(P-AMPKα)和磷酸化LKB1蛋白(P-LKB1)的表达。计算AMPK活性。结果:与NC组比较,HF组大鼠BW、FFA、TG、FPG、FINS均升高(P<0.05～P<0.01),脂联素水平降低(P<0.05),骨骼肌组织中P-AMPKα和P-LKB1蛋白表达降低,AMPK活性降低(P<0.05)。结论:高脂饮食诱导大鼠营养性肥胖,降低LKB1和AMPK的活性,从而导致TG和TCH的合成增加,血糖升高,形成胰岛素抵抗。

Objective：To investigate the expressions of AMP-activated protein kinase（AMPK） and LKB1 in adipose tissues of normal-fed rats and high-fat-fed rats,and explore the impact of AMPK and LKB1 on the metabolism of glucose and lipid.Methods：Thirty male six-week age Sprague-Dawley rats were randomly divided into two groups：15 were fed with normal control diet as NC group,the rest 15 were fed with a high-fat diet as HF group.After 16 weeks,the average body weight（BW） in HF group were over 20% higher than in NC group.All rats were weighed under anesthesia.The levels of free fatty acid（FFA）,triglyceride（TG）,total cholesterol（TCH）,fasting plasma glucose（FPG） and fasting insulin（FINS） in serum were measured.After all rats were killed,the protein levels of AMPKα,P-AMPKα and P-LKB1 in adipose tissues were analyzed with Western blot.Results：Compared with NC group,the levels of BW,FFA,TG,FPG and FINS in HF group were significantly higher（P0.05）.In adipose tissues,the expressions of P-AMPKα and P-LKB1 in HF group were lower than those in NC group（P0.05）.Conclusions：High-fat nutrition diet induces the activities of LKB1 and AMPK,promoteds the synthesis of TG,increases blood glucose,induces obesity and insulin resistance in rats.