| Objective:This paper was to investigate how exhaustive exercise and contusion affected skeletal muscle satellite cells and Myostatin (MSTN) in rat.Methods:24wistar male rats were randomly divided into four groups (n=6):control group (C)、 exhaustive exercise groups.The exhaustive exercise groups were given disposable treadmill exhaustive exercise and slaughtered after exhaustion instantly and24hours and48hours (EO, E24, E48).All of the exhaustive exercise group and the control group were anesthetized at different time points after the last exhaustive exercise and in a quiet state,Then the myocardial and the left gastrocnemius was taken down from rats after slaughtered. The gastrocnemius was divided into two.One of them were used to cell culture experiments at once,the other gastrocnemius and myocardial were kept in storage with liquid nitrogen which was detected the changes of MSTN content.Contusion group:3wistar male rats were selected for contusion experiments.They were divided into contusion instantly group(D0)、24hours (D24) and48hours(D48),All group were respectively anesthetized at contusion instantly and24hours and48hours after contusion experiments.The left gastrocnemius was taken for a cell culture experiments immediatly.In addition,the left gastrocnemius was also taken for cell culture experiments from a newborn rat.Result:(1) The result of muscle cell culture:Highly purified satellite cells with potential of muscle regeneration could be acquired in vitro by digestion and separation of rat muscle.All groups of the muscle satellite cell culture except newborn group were proliferated slowly at the incipient stage of culture.They proliferated significantly at the fifth day and covered with most Petri dish with a peak at the seven day, then the growth of muscle satellite cells became slow down. Compared with each other group,we can find out the content of muscle satellite cells in the newborn rat group was the highest,and the speed of proliferated was the fastest, we could seen a small amount of spindle cell only the next day after culture in the newborn rat group,muscle statellite cell was proliferated largely on the fourth day. When they were cultured at five days,satellite cells were together fused form into multi-core tube.The content of muscle satellite cells was least in the quiet control group which the speed of proliferated was slowly;The speed of proliferated in exhaustive exercise group and contusion group were between newborn group and control group.The one of contusion group was more faster than exhaustive exercise group.(2) The results of ELISA showed that there were significantly difference in the content of MSTN after an exhaustive exercise.Compared with the control group,the content of MSTN in skeletal muscle and the cardio muscle decreased significantly in Exhaustive exercise groups E0,E24,E48(P<0.01).But there were no significant change among these exhaustive exercise groups.Conclusion:(1)It showed that the speed of proliferated of exhaustive exercise and contusion groups were more faster than the control group and the number of muscle satellite cells also was more than the contusion group.It turned out that both of exhaustive exercise and contusion had the similar way to repaired of damage with a different extent.On the other hand,the newborn mice muscle had more satellite cells under no stimulated condition and it possesses very stronger proliferation ability,which indicated that muscle satellite cells of new born mice were not in a resting state in the body.(2)By compared with control group,the contents of MSTN in skeletal muscle and the cardio muscle were lower than control group during exhaustion exercise and recovery period,and there were no significant differences among exhaustion exercise groups (E0,E24,E48).It indicated that exhaustion exercise can deacrease the content of MSTN,and MSTN may be a negative adjustment in muscle satellite cell activation and repair process. |
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