Expression Of Myogenin And Myod Of Rats Skeletal Muscles In Different Duration After Exhaustive Exercise

The purpose of this study is to explore the dynamic changes of MyoD and Myogenin during the repair of skeletal muscle injury caused by movement and determine the repair function of MyoD and Myogenin after the skeletal muscles are injured. Set different duration after injury to observe the expression of MyoD and Myogenin.Methods:take male Wister rats as the objects and do adaptive training in groups. Then take exhaustive centrifugal treadmill exercise and result in skeletal muscle injury. Immediately after injury, blood from abdominal aorta after 6,12,24,48h and 4,7d, then put them to death and separate gastrocnemius in both hind legs. Measure the content of serum creatine kinase,malondialdehyde and superoxide dismutase and the genetic expression of MyoD and Myogenin in skeletal muscles after injury in order to determine the repair function of MyoD and Myogenin after the skeletal muscles are injured caused by movement.Results:after the skeletal muscles of rats were injured, the form of muscles changes immediately, the most serious process of change happens in the 48th hour, followed by gradual recovery; serum creatine kinase increases significantly in the 6th hour up to 48th hour, the content is the highest in the 24th hour and it's back to normal at the 4th day; the cell membrane MDA of skeletal muscles increases at first and then decline while SOD declines at first and then increases, the peak in both groups appear in the immediate group; mRNA of MyoD and Myogenin reach the peak in the 12th and 24th hour separately.Conclusion:single centrifugal to exhaustion exercise will cause micro-damage in skeletal muscle of rats. In morphology, skeletal muscle fibers have morphological changes, muscle nuclei deform and inflammatory cells appear, with the recovery time they gradually return to normal; serum creatine kinase of rats elevate and with the change of injury recovery time, they gradually decreased to normal levels; lipid peroxidation occurs in skeletal muscle cell membrane, the specific expression is that during the centrifugal to exhaustion exercise, MDA increases at first and then decreases while SOD decreases at first and then increases; MyoD and Myogenin changes after the skeletal muscles are injured and then reach the peaks which means MyoD and Myogenin can promote the repair process after the skeletal muscles are injured.