Effects of low level laser therapy on a muscular performance in rats undergoing a physical training

Abstract

Low-level Laser Therapy (LLLT) is a therapeutic resource that has special properties capable of producing effects on cellular bioenergetics. This therapeutic modality has been largely studied as an adjunct to physical exercise, yet its biological and molecular mechanisms are still unclear. The aim of this study is to evaluate the effects of LLLT on muscle performance in rats undergoing aerobic exercise training. Twenty-four male six-week-old Wistar rats will be randomly divided into three groups (n=8): sedentary control (CS), trained (T), trained, and irradiated with LLLT (TL). The physical training protocol will be performed on a motor-driven treadmill at 60% of the maximum effort, 1 hour/day, 5 days per week for 8 weeks. A laser AsGaAl (continuous wave, 808 nm, tip area of 0.00785 cm2, power 30 mW, application time 47 s, fluence 180 J/cm2; 3.8 mW/cm2; total energy 1.4J) will be used after a training session in number on four spots in each of the animals back legs (maximum gluteus, quadriceps, tibialis anterior and gastrocnemius). In order to analyze the effect of LLLT on aerobic performance, will be conducted an analysis of lactate, NO production (Griess Reaction), lipid peroxidation, and protein expression of SOD (iminohistoquímica). Furthermore, histochemical techniques will be used to investigate the morphology and morphometric analysis of trained animals and those subjected to treatment with LLLT. It is hoped that this project will bring a significant contribution to the understanding of some mechanisms of action activated by LLLT associated with physical training, optimizing its use as an adjunctive resource in rehabilitation and sports medicine.(AU)