耐力运动对大鼠葡萄糖运载体基因表达及转位的影响

目的　研究耐力运动对大鼠骨骼肌细胞葡萄糖运载体 4(glucosetransporter 4,GLUT4)基因表达及转位机制的影响。方法　将SD大鼠随机分为两组 :对照组和耐力运动组。耐力运动组大鼠进行 6周游泳训练。用Western印迹法检测大鼠骨骼肌细胞内膜和外膜的GLUT4蛋白含量 ,用Northern杂交法和斑点印迹法检测大鼠骨骼肌细胞内GLUT4mRNA含量。实验前后检测大鼠血清胰岛素和血糖浓度。结果　运动组大鼠经过 6周游泳训练后 ,与对照组大鼠相比 ,骨骼肌细胞内膜GLUT4含量增加 16.0 %(P <0 .0 1) ,细胞外膜GLUT4含量增加 71.9% (P <0 .0 1) ,骨骼肌细胞内GLUT4mRNA含量增加2 5 .6% (P <0 .0 1)。结论　耐力运动可增加骨骼肌细胞内GLUT4基因表达水平 ,促进骨骼肌细胞内的GLUT4从内膜向细胞外膜转位 ,从而提高骨骼肌细胞对葡萄糖的摄取和利用。

Effect of endurance training on glucose transporter gene expression and translocation in rat skeletal muscle

Objective To investigate the effect of endurance training on glucose transporter 4 (GLUT4) gene expression and translocation in rat skeletal muscle cell. Methods Experimental SD rats were randomized into two groups: control group, and endurance exercise group. Endurance exercise rats were submitted to swim for 6 weeks. After skeletal muscle plasma membranes and the intracellular membranes were prepared and separated, GLUT4 protein was detected by Western blot analysis.GLUT4 gene expression as determined with dot blot and Northern blot in both groups. And plasma glucose and serum insulin concentration of rats was detected. Results After six weeks of endurance training, Western blot analysis showed that intracellular membrane GLUT4 protein of exercise rats skeletal muscle increased by 16.0 %(P< 0.01 ) and plasma membrane GLUT4 protein increased by 71.9 % (P< 0.01 )as compared with the control rats. Dot blot revealed that GLUT4 mRNA increased 25.6 % in skeletal muscle cells compared with the control rats(P< 0.01 ).Conclusion Endurance training can increase gene expression of GLUT4 in rat skeletal muscle cells, and enhance translocation of GLUT4 from intracellular membranes to plasma membranes,raising the amount of GLUT4 protein in plasma membranes in rats, which may increase the utilization of glucose in skeletal muscle.