Effect Of Early Treadmill Exercise And Massage On Activ Ative Factors Of Muscle Satellite Cells After Acute Injury Of Skeletal Muscle In Rats

Objective To study the effect of treadmill exercise and massage shortly afte r acute injury on expression of key growth factor in muscle satellite cells activat ion,insulin-like growth factor-1(IGF-1),and mitogen-activated protein ki‐ nase(MAPK)/ mitogen-activated protein kinase kinase(MEK)/ extracellular regulate d protein kinases(ERK)1/2 signaling pathways in muscle satellite cell in rats.Methods A total of 40 SPF male adult Sprague-Dawley rats were randomly divided into groups A(n = 8),B(n = 8),C(n = 8),D(n = 8)and E(n =8).Group A did not receive any treatment,while the other rats were contused t he gastrocnemius muscle with self-made impactor.Group B received no intervent ion,group C and group D received massage and treadmill exercise shortly after injury,respectively,while group E received both treadmill exercise and massage shortly after injury.At the model was established,Samples of gastrocnemius wer e obtained from all the rats 24 hours after injury,and observed under HE staini ng,detected the expression of MyoD1 and MyoG mRNA with reverse transcripti on polymerase chain reaction(RT-PCR),and expression of IGF-1,p-MAPK,p-M EK and p-ERKI/2 protein with Western blotting.Results The expression of MyoD1 mRNA was more in groups C,D and E than in group B,which was the most in groupC;less expression of MyoG mR NA,which was the most in group E(P < 0.05).The expression of p-MAPK,pMEK and p-EPK1/2 was more in groups C,D and E than in group B,which w as the most in group D(P < 0.05).The expression of IFG-1 increased in groupC compared with that in group B(P < 0.05),and it decreased in group D(P< 0.05).Conclusion Early intervention of treadmill exercise and massage may promo te the activation of muscle satellite cells in different ways.