目的 探讨肥胖大鼠肝脏组织腺苷酸激活蛋白激酶(AMPK)的表达及其对肝脏脂质沉积的影响。方法 选用18只刚断乳的SPF级SD雄性大鼠,随机挑选6只普通饲料喂养为正常组,另一组12只高脂饲料喂养,12 w后成功建立肥胖模型大鼠6只。分别检测体重、Lee指数、内脏脂肪、肝湿重等指标。通过油红O染色和检测肝脏甘油三酯(TG)、总胆固醇(TC)含量评估两组大鼠肝脏脂质沉积的情况。采用Western印迹检测大鼠肝脏磷酸化(p)-AMPK/AMPK、p-ACC/ACC水平。结果 与正常组大鼠相比,肥胖组大鼠体重与Lee指数、附睾脂肪、肾周脂肪量、肝湿重、肝脏内TG与TC含量均显著升高,油红O染色结果显示肥胖组肝脏脂质沉积较正常组明显增多。Western印迹结果显示,与正常组大鼠比较,肥胖组大鼠肝脏p-AMPK/AMPK和p-ACC/ACC表达明显降低。两组大鼠肝脏组织中p-AMPK、p-ACC表达水平与肝脏TG、TC呈负相关。结论 高脂饮食诱导食源性肥胖大鼠可降低AMPK的活性,从而导致肝脏组织TG、TC合成增加,脂质在肝脏组织中沉积增加。
Objective To explore the expressions of AMP-activated protein kinase in the liver and the relationship with lipid deposi- tion. Methods 18 SPF SD male rats were chosen and then randomly divided into normal (n = 6) and high-fat groups (n = 12). After suc- cessful modeling, 6 rats were in obese group (n=6). Rat weight, visceral fat and liver weight were compared. Lipid deposition was evalua- ted by oil red O dye and total cholesterol (T C) and triglyceride (TG) were measured: The expression of AMP activated protein kinase (AMPK) and acetyl-CoA earboxylase (ACC) in the liver were measured by Western blot. Results Compared with those of normal group, body weight, epididymal fat, perirenal fat, liver weight, TG and TC levels in the liver of obese group were significantly increased. The lipid deposition in the liver of obese rat was significantly increased compared with that of normal group. The phosphorylation AMPK (pAMPK) and ACC (pACC) were decreased in the liver of the obese group. The expression of pAMPK and pACC were negatively correlated with TG and TC level in the liver. Conclusions High-fat diet could induce obese, and then reduce AMPK activity, increase TG and TC level in the liver and result in lipid deposition in the liver.