EFFECT OF EXTREMELY LOW-FREQUENCY ELECTROMAGNETIC FIELDS ON PROMOTING MYOGENESIS IN THE EARLY PROCESS OF DENERVATED MUSCLEATROPHY

Abstract

Objective: To investigate the effects of extremely low-frequency electromagnetic fields (ELF-EMF) on myogenesis during the early stage of denervated muscle atrophy in Sprague-Dawley (SD) rats. Methods: a total of 36 female SD rats were fed in cages and divided into three groups: the normal control group, the muscle atrophy group and the 10[Formula: see text]Hz/1.5[Formula: see text]mT magnetic field group. The rats in the 10[Formula: see text]Hz/1.5[Formula: see text]mT magnetic field group received a magnetic field intervention for 2[Formula: see text]h per day. The posterior muscle groups of the lower limbs of rats were sampled on the first, second, third and fourth weeks for evaluating the underlying changes. The harvested tissues were stained with hematoxylin–eosin (HE) dye to observe the morphology of the muscle atrophy and to measure the muscle fiber cross-sectional area ratio. A reverse transcription polymerase chain reaction was used to detect the expression of Myf5 mRNA in each group. The myogenesis-related proteins in the harvested muscle tissue were detected by western blot assay. Results: (1) HE staining showed that with the extension of denervation time, the structural disorder of muscle fibers was aggravated, and in the second week of the denervated muscle atrophy, muscle fiber cross-sectional area tended to increase in the 10[Formula: see text]Hz/1.5[Formula: see text]mT magnetic field group. Overall muscle atrophy was inevitable. (2) Results of RT-PCR showed that the expression of Myf5 mRNA in the 10[Formula: see text]Hz/1.5[Formula: see text]mT magnetic field group was significantly high in the second week of denervation, and the difference was statistically significant compared with the muscle atrophy group (*[Formula: see text]). (3) Western blot analysis showed that the expression of MYF5 proteins in the 10[Formula: see text]Hz/1.5[Formula: see text]mT magnetic field group was significantly higher than that in the muscle atrophy group (**[Formula: see text]) in the second week of denervation. Further, the expression of MYOG protein in the 10[Formula: see text]Hz/1.5[Formula: see text]mT magnetic field group was significantly higher than that in the muscle atrophy group (****[Formula: see text]). Conclusions: 10[Formula: see text]Hz/1.5[Formula: see text]mT ELF-EMF can significantly promote myogenesis during early denervated muscle atrophy in SD rats.