Efeito da terapia laser de baixa potência sobre o remodelamento do tecido conjuntivo e a regeneração do músculo esquelético de ratos idoso

Abstract

The aging changes the activation and proliferation of satellite cells and inflammatory cells in skeletal muscle and fibroblasts promotes increased, decreased vascularization and thickening of the basal lamina. The aim of this study was to evaluate the effects of LBP on the tibialis anterior (TA) muscle of aged rats after cryoinjury on morphological, on the expression of IL-6 and IL-1 beta, distribution and collagen organization. It was performed histological photomicrographs of the TA muscle stained with hematoxylin-eosin, Picrosirius Red, and immunohistochemistry for IL-6 and IL-1beta. The results were quantitatively and qualitatively in Image J software. The study was approved by CEUA-UNINOVE and were used n= 30 legs of male rats Wistar divided into 03 experimental groups: - Group 1 Control (n= 4): animals uninjured or LBP-treated; Group 2 cryoinjury LBP untreated (n= 13) and Group 3 treated with LBP infrared cryoinjury (n= 13). The LBP was applied to muscle after 2h of induction of injury and consisted of daily application until the day of sacrifice (Groups 1, 3 or 7 days) according to the study group. We were using the parameters (λ = 780nm, 1000mW / cm2 power density, power 40mW; 3,2J total energy, time of 10s). In histomorphological analysis, seven days the treated group had a significant decrease in infiltration of inflammatory cells and increased immature fibers and new blood vessels compared to Group 7 days did not-treated (p <0.05). In the analysis of distribution and collagen organization, there was a control group difference from the group treated 7 days and non-treated (p <0.05). The expression of IL-6 by immunohistochemistry, was higher in all study groups (p <0.05) compared to control, but there was no difference between the groups treated injured or not. The IL-1beta expression, there was increased expression in 3 days treated compared to group 1 and 7 days treated. In conclusion, the LPB shown modulatory effect on muscle repair process in aged animals.