The effects of photobiomodulation on inflammatory infiltrate during muscle repair in advanced-age rats.
J Gerontol A Biol Sci Med Sci. 2019 Mar 20. Epub 2019 Mar 20. PMID: 30891589
Evaldo Moreira da Silva
Photobiomodulation (PBM) enhances muscle repair in aged animals, but its effect on the modulation of the phenotype of immune cells has not yet been determined. Rats (20-month-old) were submitted to cryoinjury of the tibialis anterior muscle and were treated with PBM. After 1, 3 and 7 days, the muscles were submitted to immunohistochemical analysis for the determination of neutrophils and macrophage phenotypes. The muscles treated with PBM exhibited a smaller number of neutrophils after one day of treatment and a greater number of both M1 and M2 macrophages after three days of treatment. The irradiated tissues exhibited a smaller amount of both macrophage phenotypes after seven days of treatment. PBM produced temporal alterations in the phenotype of the inflammatory cells during muscle repair process in advanced-age animals, indicating that these mechanisms may contribute to the beneficial effects of this therapy in the treatment of muscle injuries.