Effects of pulsed electromagnetic fields on the expression of MyoD after acute skeletal muscle contusion / 中华物理医学与康复杂志

ABSTRACT

Objective To observe the effects of pulsed electromagnetic fields (PEMFs) on histological changes and myogenic differentiation factor D (MyoD) expression in rats with acute skeletal muscle contusion ( ASMC), and to explore the effects of PEMF therapy on rats with ASMC in its very early stages. Methods Forty-two rats were randomly divided into three groups a treatment group, a control group and a blank control group. ASMC models were established with all the animals in the treatment and control groups. PEMF treatment was admin-istered to the treatment group immediately after the establishment of the ASMC model. Seven rats in each group were sacrificed at the 12th and 18th h after the models were set up. Their triceps surae muscles were sampled and treated with haematoxylin-eosin staining for study using immunofluorescence techniques and a fluorescence microscope. Re-suits In the control group at the 12th h and 18th h, HE staining showed pale cytoplasm and polymorphism in the cell nuclei ; in the treatment group these effects were significantly lighter, but in both groups it was more serious than in the blank control group. In the treatment and control groups, the fluorescence intensity of MyoD at the 18th h was higher than at the 12th h, and at each time point in both groups it was higher than in the blank control group. At the 18th h, fluorescence in the treatment group was stronger than in the control group. Conclusion MyoD expression in rats with ASMC is upregulated by thel8th h after early PEMF treatment. This might be one of the mechanisms ac-celerating the regeneration of skeletal muscles after trauma.