| Objective:To observe the effect of massage therapy on skeletal muscle structure,contractile force and self-renewal of muscle stem cells(MSC)in long-term large load exercise rats,and to explore the mechanism of Notch-Collagen V signal axis,so as to provide experimental basis for the application of massage therapy in sports medicine practice.Methods:Thirty-two 8-week-old male SD rats were randomly divided into blank control group(C),long-term large load exercise group(E),long-term large load exercise+massage therapy group(ET)and long-term large load exercise+sham massage therapy group(ES).Groups E,ES and ET did 4-week eccentric exercise(-16,60-90min/day,6 days/week)to establish a long-term large load exercise model;group ET were given massage therapy on triceps surae 6h after exercise,and the manipulation parameters were quantified with the help of FSR thin film pressure sensor,and the intensity was maintained for about 4 N,the frequency was 120 times/min and each side was 5 minutes;group ES was touched on the back of the calf in the same period.Gastrocnemius tissue was collected 24 hours after the last exercise and massage therapy for index test:(1)Transmission electron microscopy was used to observe the ultrastructure of muscle fibers and physiological signal acquisition system was used to measure the contractile force of gastrocnemius muscle in vitro.(2)Western Blot was used to detect the protein expression of Pax7,Myo D and Myogenin,and double-label immunofluorescence was used to analyze the number of quiescent Pax7~+/Myo D~-cell and cycling Pax7~+/Myo D~+cells.(3)Immunohistochemical staining was used to detect COLV expression,real-time fluorescence quantitative PCR was used to detect Col5a1and Col5a3 m RNA expression,Western Blot was used to detect NICD and RBPJ protein expression,and double-label immunofluorescence was used to observe the co-expression of Pax7 and COLV,Pax7 and RBPJ.Results:(1)Effects of massage on skeletal muscle structure and contractile force of long-term large load exercise rats:The ultrastructure of gastrocnemius in group C and ET was normal and the myofibrils were arranged neatly.Group E and ES showed myofibrillary fracture and degradation,endoplasmic reticulum and mitochondria swelling.The single and tonic contractile force in the ET group were significantly higher than those in the C,E,and ES groups(P<0.01).(2)Effects of massage on MSC self-renewal in rats with long-term large exercise:compared with group C,the expression of Pax7 and Myo D protein significantly decreased,the expression of Myoglobin protein significantly increased and the number of Pax7~+/Myo D~-and Pax7~+/Myo D~+cells was decreased significantly in group E(P<0.05 or P<0.01);compared with group E,the protein expression of Pax7 and Myo D was significantly increased,the protein expression of Myoglobin was significantly decreased,and the number of Pax7~+/Myo D~-and Pax7~+/Myo D~+cells was significantly increased in group ET(P<0.05 or P<0.01),there were no significant differences in the above indexes in ES group(P>0.05).(3)Effects of massage on Notch-Collagen V signaling axis in long-term large load exercise rats:Compared with group C,COLV expression(P<0.05),Col5a1 and Col5a3 m RNA expressions(P<0.01)and NICD and RBPJ protein expressions(P<0.01),and the co-location expressions of Pax7 and COLV,Pax7 and RBPJ was significantly decreased in group E;Compared with E,the expression of COLV(P<0.01),Col5a1 and Col5a3 m RNA expression(P<0.05 or P<0.05),NICD and RBPJ protein expression(P<0.01),and the co-location expression of Pax7 and COLV,Pax7 and RBPJ was significantly increased in ET group,there were no significant differences in the above indexes in ES group(P>0.05).Conclusion:(1)massage can promote the repair of skeletal muscle ultrastructural damage and increase muscle contractility in long-term large load exercise rats.(2)massage can promote the self-renewal of skeletal muscle MSC in long-term large load exercise rats,and its mechanism may be related to Notch-Collagen V signal axis. |
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