Effects Of Great Intensity Centrifugal Exercise On The Skeleton Muscle Fiber Type And MyoD,Myogenin Expression In Growing Rats

Goal:The objective of this study was to investigate the percent of all kinds of muscle fibers,and MyoD,myogenin expression change situation in growing rats soleus muscle and quadriceps muscle.The purpose is discussing the great intensity centrifugal movement whether can arouse muscle fibers and MHC hypotype transforms mutually,as well as whether to MyoD,the myogein expression to have the influence in growing rats.For young people's growth,the movement selection and the movement training provide the theory basis.Method:48 male growing Sprague-Dawley rats randomly divide into 3W,6W,the 9W control group(NC,n=8) and 3W,6W,the 9W training group(DT,n=8);24 male adult SD rats randomly divide into 3W,6W,the 9W training group(MT,n=8).According to Bedford four level of load train plan,DT group and MT group, in slope for - 10°runs on the stage to carry on the speed is the 26.8m/min downhill runs,Every week trains for 5 days,each time trains 30min.Control group and movement group rats were killed by separately after peaceful condition and movement latter 24 hour.Takesleft side of rats hind legs soleus muscle and quadriceps muscle.The typeⅠmuscle fibers and typeⅡmuscle fibers were distinguished through ATPase coloration and isoforms of MHC were separated into MHCⅠ,MHCⅡa,MHCⅡb and MHCⅡx through SDS-PAGE electrophoresis.RT-PCR examines MyoD, the myogein expression.Result:(1) After great intensity centrifugal movement,compares with NC group,DT group typeⅠmuscle fibers of soleus muscle number density and the superficial density increase(P＜0.05);(2) After great intensity centrifugal movement,compares with NC group,DT group typeⅡmuscle fibers of quadriceps muscle superficial density decrease(P＜0.05);(3) The great intensity centrifugal movement causes DT group soleus muscle and quadriceps muscle MHCⅡb%decrease(P＜0.05),MHCⅡx%increase(P＜0.05);(4)After great intensity centrifugal movement 3W,in growing rats soleus muscle MyoD expression upward(P＜0.05),myogenin expression downward(P＜0.05),(5)Great intensity centrifugal movement various time intervals, growing rats quadriceps muscles MyoD expression upward(P＜0.05); (6) After great intensity centrifugal movement,DT group quadriceps muscles MHCⅡx%have the high relevance with the MyoD expression,Correlation coefficient is 0.83,P＜0.05;With MHCⅡa%nverse correlations,correlation coefficient for - 0.44,P＜0.05.Conclusion:(1) The great intensity centrifugal movement can cause the growing rats different type skeleton muscle fiber the number density and the superficial density changes, particularly the superficial density change is more remarkable.(2) The great intensity centrifugal movement can cause between growing rats skeletal muscte MHC hypotype to have the transformation,The transformed direction is:①MHCⅡb translate into MHCⅠ,MHCⅡx,MHCⅡa;②MHCⅡx approaches MHCⅡa transformation;③MHCⅡx,MHCⅡa translate into MHCⅠtogether.(3) The great intensity centrifugal movement to growing rats skeletal muscle in MyoD,the myogenin expression has certain influence.