| Objectiv：This paper research on the influence of different loads of sport injury on ratskeletal muscle after the completion of the natural repair process and drug treatmentof inflammatory cell infiltration (FC), satellite cells (SC) activation of myogenicregulatory factors MyoD protein levels. The purpose of this study is to provide atheoretical basis for the prevention of skeletal muscle injury, diagnosis and choose thebest injury treatment time.Method：Select64wister female rats,6-8week-old, for the study, and randomlydivided them into four groups: group S is sedentary control group(amount16); groupN is no-load group(amount16); group M is medium-load group(amount16); group Pis large-load group(amount16). Establishment the rat model of sports injuries, andinduce damage in rat skeletal muscle (reference field modeling). The rats arerandomly divided into treatment group (T) and the non-treated group (n). Group T aregiven drug intervention after24h till10d (with Yunnanbaiyao aerosol spray).Meantime, group n are given physiological saline with the same dose. After eightweeks of training in rats, each training group16rats were drawn immediately aftertraining stops,24h,1d,4d,7d, and10d respectively. Observe the number changes ofFC and SC under an optical microscope, and detect the MyoD protein expressionlevel by immunohistochemistry labeling.Result：1、After treadmill exercises for eight weeks and induction of skeletal muscleinjury in rats, different load T-group and n-group’s FC peaked after24h, followed bypersistent decline. After the statistical test, PT, Pn, MT, Mn, NT, Nn FC group atdifferent times higher than the number of the same period the S group, with astatistically significant difference (P<0.01). There were significant changes in thegroup PT, NT compared to group Pn、Nn after injury4d (P<0.01), and there weresignificant changes in the group MT compared to group MN(P<0.05). There weresignificant changes in the group PT, NT compared to group Pn、Nn after injury7d (P<0.05). There were not statistically significant Mn in group MT compared to groupMn. After10h, among all different load exercise groups comparing to group S, only Pand N groups was statistically significant (P<0.01), while there were no statisticallydifference in group T compared to group n.Different load n-group’s FC peaked after1d. Then, FC gradually decreased andthe number of this group was close to S. Comparison between groups, group P’s FChad the maximum number, followed by group N, and the group M had the minimumnumber. This means the medium-load is more conducive to damage repair. Therecovery of group P is slow. This means there is damage accumulation phenomenon.After repair treatment, the downward trend of FC is consistent with the number ofnon-treatment group, faster than group n. This means that drug treatment acceleratesthe repair function of muscle fibers, which is conducive to regeneration and repairafter injury.2、After treadmill exercises for eight weeks and induction of skeletal muscleinjury in rats, SC gradually increased in each group after exercise, and peaked after7d,then continuing decline. After the statistical test, PT, Pn, MT, Mn, NT, Nn SC groupsat different times were higher than the S group at the same period, with a statisticallysignificant difference (P<0.01). Among different load groups of T and n after4d, onlyMT group and Mn group was statistically significant (P<0.05). Different load groupsof T and n had a very significant difference after7d (P<0.01). Compared group T withgroup n after10d, only group M had a statistically significant difference (P<0.05).In the experiment, we found that different loads group of T and n’s SC were fewat the first day after injury, then increasing gradually, and peaked after7d, thenpersistent decreasing. Comparing among all groups, group M’s SC had the maximumnumber, the second was group N, the lowest was group P. This means that mediumload intensity is more conducive to activate SC. The recovery of group P was slow,which means that there is damage accumulation phenomenon. After repair treatment,the decline trend of SC was consistent with group n, however, the recovery is fasterthan group n. This means that the drug treatment accelerated the disappearance ofinflammatory response, and had a promoting role in activating the repair and regeneration of SC muscle fibers.3、MyoD expression at different loads were few immediately after injury express,and peaked after1d, then decreased gradually. Group n: MyoD began to expressimmediately after injury, and peaked after24h. The MyoD of group Mn were less thangroup Nn and Pn, this means that the skeletal muscle of group M have theanti-damage ability. After7d, the MyoD protein expression of groups Mn and Nnwere both close to the group S, however, the group P is still very high, which meansthat there may exist repeated muscle injury in group Pn. Group T had the similar trendwith the group n, and returned to the group S after7d. Compared group T with groupn of different load groups, the MyoD expressions of group T were all lower thangroup n.4、Treadmill-induced damage in rat skeletal muscle and after drug treatment withYunnanbaiyao, the changes of FC infiltration, the number of activated SC, satellitecells, and different expression levels of MyoD protein. Among different loads T groupafter4d, the amount of FC and MyoD expressions peaked while the active amount ofSC were low. After7d, while the amount of FC and MyoD expressions decreasing, theactive amount of SC begun to increase and peaked. While decreasing of FC gradually,the amount of SC begun to decrease until the completion of the restoration of theentire drug treatment.After the therapy, the amount of FC and the MyoD expressions had changes ofdelay and timing consistency. Meantime, Yunnanbaiyao accelerated the activation ofSC during the process of wound healing in rats, and strengthed the MyoD expressions,and also accelerate the elimination of inflammatory response.Conclusion：1.After loads of different sports injury in rat skeletal muscle, there islinear relationship between the amount of rat skeletal muscle FC and the amount ofSC、MyoD activation during the periods of natural repair and drug interventionregeneration, that is, a certain amount of FC infiltration can promote the proliferationof activated SC and MyoD, but too much amount if FC and MyoD infiltration cansuppress the activation of SC.2.Yunnanbaiyao has significantly inhibited impact on the injury FC skeletal muscle infiltration, can shortened the inflammation process, promote muscle injuryMyoD protein expression, promote activation, proliferation and differentiation of SC,and accelerate the repair and regeneration of damaged muscle fibers.3.After loads of different sports injury in rat skeletal muscle, group M are easierto repair and regeneration than groups N and P during the periods of natural repair anddrug intervention regeneration. |
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