二甲双胍对糖尿病大鼠脂肪组织AMPK和PPARγ的表达及胰岛素抵抗影响

Effect of metformin on expressions of AMPKα_2,PPARγ and insulin resistance in adipose tissues of type 2 diabetic rats

目的:观察二甲双胍对2型糖尿病模型大鼠脂肪组织中腺苷酸活化蛋白激酶α2(AMPKα2)及过氧化物酶体增值物激活受体γ(PPARγ)的表达,及其对胰岛素抵抗的影响。方法:高脂饮食伴一次性腹腔注射STZ的方法制备2型糖尿病模型,造模成功后随机分为模型组(DM-C)和治疗组(DM-T)。DM-T组给予盐酸二甲双胍灌胃治疗。测定大鼠治疗前后的体质量,实验末测定各组大鼠肾周及睾周脂肪质量,并检测各组大鼠血糖、胰岛素水平,计算大鼠脂体比,胰岛素敏感指数。同时以半定量逆转录-聚合酶链反应法(RT-PCR)检测各组大鼠脂肪组织AMPKα2及PPARγmRNA的表达。结果:与DM-C组比较,治疗组大鼠脂肪组织AMPKα2及PPARγmRNA的表达及血清胰岛素、胰岛素敏感指数显著增高(P<0.05);DM-T组大鼠血糖显著降低(P<0.05)。结论:二甲双胍可能通过上调2型糖尿病大鼠脂肪组织AMPKα2及PPARγmRNA的表达,调节机体糖代谢,改善胰岛素敏感性。

OBJECTIVE To examine the effects of metformin on expressions of AMPKα2, PPARγ and insulin resistance in adipose tissues of type 2 diabetic rats. METHODS To prepare type 2 diabetes models with high fat diets accompanied with intra-peritoneal injection of STZ once and divide the rats to model group（DM-C）, treatment group （DM-T）. After successful preparing the models, DM -T group was treated with metformin by intragastric administration. The rat body weight before and after treatment was evaluated. The fat weight of adipose tissues around kidney and testicle at last was measured. Tested serum glucose, insulin and calculated insulin sensitivity index（ISI） and adipose weight/body weight. The expressions of AMPKα2, PPARγ in adipose tissues were detected with RT-PCR. RESULTS The levels of AMPKa2, PPARy MRNA expressions,the levels of serum insulin and ISI in DM-T were higher than those of DMC; The level of serum glucose was lower in DM T than that of DM C（P〈0. 05）. CONCLUSION Mctformin may regulate glycometabolism and improve insulin sensitivity by up-regulating the levels of AMPKα2, PPARγ MRNA expressions in adipose tissues of type 2 diabetic rats.