Pulsed Electromagnetic Field Elicits Muscle Recovery via Increase of HSP 70 Expression after Crush Injury of Rat Skeletal Muscle

抄録

[Purpose] The present study investigated the effects of electromagnetic field applied at different time points on muscle recovery process through observation of the expression of HSP 70 protein and histological changes in a rat muscle crush injury model. [Subjects and Methods] Fifty-four male Sprague-Dawley rats were subjected to crush injury of the left extensor digitorum longus muscle. The animals were randomly assigned to the control (CON), pulsed electromagnetic fields (PEMF), delayed PEMF (DPEMF) groups and pulsed electromagnetic fields were administered from 1 or 3 days after muscle injury. Western blotting, immunohistochemistry, and hematoxylin-eosin staining was used to evaluate of heat shock protein (HSP) 70 expression to assess muscle recovery. [Results] Muscle injury-induced decrease of HSP 70 protein was increased and recovered by electromagnetic field application in the PEMF and DPEMF groups. Moreover, atrophy and irregular arrangement of muscle fiber caused by crush injury improved in both the PEMF and DPEMF groups. [Conclusion] In the rat model of muscle crush injury, PEMF induced muscle recovery via increased HSJP 70 protein.