Low-level laser therapy modulates musculoskeletal loss in a skin burn model in rats.

PURPOSE To investigate the effectiveness of low-level laser therapy (LLLT) on gastrocnemius muscle morphology and Myod immunoexpression in a model of dorsal burn in rats. METHODS Sixteen male Wistar rats were distributed into two groups: control group (CG): rats submitted to scald burn injury without treatment and laser treated group (LG): rats submitted to scald burn injury and treated with laser therapy. Fourteen days post-surgery, gastrocnemius muscle was evaluated being the specimens stained with HE and morphometric data was evaluated. MyoD expression was assessed by immunohistochemistry. RESULTS The results showed that laser treated animals presented more organized tissue morphology compared to the non-treated animals, with a higher number of nucleus in the fibers. Also, the cross sectional area of the fibers and the MyoD immunoexpression in the laser treated groups was higher. CONCLUSION Low-level laser therapy had positive effects on gastrocnemius muscle, improving tissue muscle morphology, increasing cross sectional area and MyoD immunoexpression.