Effects Of Different Mode Of Exercise On Healing Process Of Acute Skeletal Muscle Injury Of Rats

Purpose:To investigated effects of different exercise modes (the eccentric exercise, the concentric exercise, and the exercise combining these two) on mechanics of materials, Desmin, MHC-II and collagen type I and III in the healing process of acute skeletal muscle injury of rats, choose the appropriate exercise mode to rehabilitate the acute skeletal muscle injury, and guide the clinical rehabilitation. Methods:152 adult female SD rats were selected and divided randomly into 7 groups:blank control group (BC group, n= 8), immediate group (I group, n= 8), the first week group (1W group, n= 8), the natural-healing group (NH group, n= 32), concentric-exercise group (CE group, n= 32), eccentric-exercise group (EE group, n= 32) and the combination group (CO group, n= 32). After one week the model of gastrocnemius acute sprain injury was caused, the CE group, EE group and CO group were carried on concentric exercise, eccentric exercise, and the combined exercises of concentric and eccentric respectively for 4 weeks.The different groups have different drawing materials time. IM Group was immediately after the modeling,1W group was 7 days after modeling, the BC group was 18 days after modeling and other groups were respectively 14 days,21 days,28 days and 35 days after modeling. In the meaning time the material mechanics specimen and immunohistochemistry sections were prepared to detect the ultimate stress, the ultimate strain, the Young's modulus, Desmin, MHC-II, COL-I and COL-III of rat's gastrocnemius. Results:Exercise had definite influence on the healing process of skeletal muscle acute injury. And different exercise mode had different effects; The concentric exercise could promote and accelerate the synthesis of Desmin and MHC-â…¡of the injured skeletal muscle, and inhibit the synthesis of COL-â… and COL-III relatively, thus speed up the recovery of the ultimate stress, the ultimate strain and the Young's modulus, so could recover the strength and flexibility of skeletal muscle effectively; Eccentric exercise could improve and maintain the Desmin level of injured skeletal muscle for a long period of time, but the increase of the COL-â… and COL-III level causing by the eccentric exercise may could competitively inhibit the expression and synthesis of MHC-II, so that the levels of MHC-II was reduced relatively; Eccentric exercise could accelerate the restoration of ultimate stress in injured skeletal muscles, but the effect might delay the recovery of the ultimate strain and Young's modulus in injured skeletal muscles. Thereby eccentric exercise could increase the strength of skeletal muscle while reducing the flexibility.; The combined exercise of concentric and eccentric was not as obvious as the concentric exercise to increase the level of MHC-â…¡, but it could get faster recovery in skeletal muscle's structure and strength by raising the levels of Desmin, COL-â… and COL-â…¢, and provide a guarantee of the structure and strength in order to functional reshape the skeletal muscle in the latter part of recovery. Conclusion:The most effectively exercise rehabilitation way to remodel the structure and function of skeletal most effectively after acute skeletal muscle injury was an exercise mode that combination of concentric and eccentric exercise, taking the concentric exercises mainly.