罗格列酮对高脂饲养大鼠骨骼肌AMPK活性的影响

Effects of Rosiglitazone on activities of AMPK in the skeletal muscle of high-fat fed rats

目的观察罗格列酮对高脂饲养大鼠骨骼肌AMP激活的蛋白激酶(AMPK)α、葡萄糖转运体4(GLUT4)、胰岛素受体底物1(IRS1)及过氧化物酶体增殖物激活受体γ(PPARγ)表达的影响,为临床有效的预防和控制脂毒性提供科学依据。方法雄性Wistar大鼠30只,随机分为对照、高脂和高脂加罗格列酮[1 mg/(kg.d)]三组,每组10只。喂养5个月后,采用Real time PCR法测定大鼠骨骼肌中AMPKα1、AMPKα2、GLUT4的mRNA水平,RT-PCR法测定IRS1、PPARγmRNA的表达,Western blot法测定P-AMPK、T-AMPK和GLUT4的含量。结果高脂组大鼠除AMPKα1和IRS1的mRNA表达无变化外,AMPKα2、GLUT4、PPARγ的mRNA水平及P-AMPK、T-AMPK、GLUT4的蛋白水平均比对照组降低(P<0.01或P<0.05)。与高脂组相比,罗格列酮显著增加大鼠骨骼肌GLUT4、PPARγ、IRS1的mR-NA水平及P-AMPK、GLUT4的蛋白水平(P<0.01或P<0.05),而对AMPKα1、AMPKα2的mRNA水平和T-AMPK的蛋白水平无明显影响。结论罗格列酮可增加高脂喂养大鼠的骨骼肌P-AMPK、GLUT4、PPARγ和IRS1的表达,提示其具有参与改善胰岛素抵抗、缓解脂毒性的作用。

Objective To investigate effects of Rosiglitazone on activities of AMPK （AMP-activated protein kinase）, GLUT4 （glucose transport 4）, IRS1 （insulin receptor substrate 1 ）, and PPARγ （peroxisome proliferator activated receptor 7） in the skeletal muscle of high-fat fed rats. Methods Male Wistar rats were randomly divided into three groups：the control group （ N, n = 10）, the high-fat diet group （HF, n = 10）, and the Rosightazone-treated group （HF＋ Ros, n = 10）. After a high fat feeding for four months, rats in the HF ＋ Ros group were treated with Rosiglitazone at a dose of 1 mg/（kg·d） orally for one month. Skeletal muscles of all animals were gained for further analysis. The mRNA levels of AMPKa1, AMPKa2, and GLUT4 were determined using real time PCR and of IRS1 and PPARγ using RT-PCR. Protein levels of total AMPK, P-AMPK, and GLUT4 were determined by Western blot. Results Compared with the controls, the mRNA levels of AMPKa2, GLUT4, and PPARγ were reduced, and also protein expressions of total AMPK, P-AMPK and GLUTd were decreased in rats with a high-fat diet. But the AMPKa1 and IRS1 mRNA levels had no changes. Compared with the HF group, Rosiglitazone increased mRNA levels of GLUT4, PPARγ and IllS1 and enhanced protein expressions of P-AMPK and GLUT4. But there were no changes in AMPKa1, AMPKa2, and T-AMPK. Conclusion Rosightazone could increase expression of P-AMPK, GLUT4, PPARγ, and IRS1 in high-fat fed rats, which suggests that it could ameliorate insulin resistance.