Effects Of Endurance Training On Expression Of GLUT-4 In AMPKα2-KO Mouse Skeletal Muscle

Biochemical adaptation of skeletal muscle to exercises includes increases in some key proteins involved in glucose uptake, such as glucose transpoter-4(GLUT4). The intracellular pathways involved in eliciting these exercise training-induced increases in protein expression remain largely unknown. The 5'-AMP-activated protein kinase (AMPK) has been proposed as a signaling molecule involved in transmitting an "exercise signal" to the nuclei of the muscle cell. This is in part based on thefinding that the AMPK is activated by in vitro electrical induced contractions of rodent skeletal muscles. Therefore, the purpose of the present study was to investigate the importance of the catalytic AMPK a 2 subunit in expression of GLUT4 protein and gene.In our study, AMPKα2 whole body knock and corresponding wild-type mice that had undertaken a 4-week program of treadmill training. The speed of treadmill was 12m/min. Muscles were removed from anesthetized animals on day 29 14-16 h after the last exercise bout, quick-frozen by aluminum tongs pre-cooled in liquid nitrogen, and store at-80℃.We measured AMPKα2 and GLUT4 protein and gene expression with western blotting and real-time PCR, respectively. Additional experiments were conducted to measure some indexes include blood glucose, blood insulin and muscle glycogen.In both wild animals andα2-K0 animals, the expression of AMPK a 2 protein and gene increased in response to exercise, whereas the a 2-KO did not affect training-induced increases in expression of protein and gene of GLUT4. The results of this study suggested that AMPK a 2 may not be essential for the regulation in GLUT4 protein and gene levels and metabolic adaptation of skeletal muscles to exercise training.