Análise da ação do laser em baixa potência na capacidade física e alterações musculares em ratos idosos submetidos a treinamento aeróbio

Abstract

The effect of physical activity in the elderly shows very positive results such as increased blood flow, muscle strength and speed of oxidative capacity and reduced glycogen depletion. It is observed in literature using low power laser (LBP) in patients undergoing exercise has shown results that demonstrate increased muscle and decreased performace or delay muscle fatigue. This study aimed to verify the action of LBP in physical function in protein expression of inflammatory mediators IL-6 and TNF-α and morphology of the gastrocnemius muscle of aged rats. 30 male Wistar rats , seniors aged 24 months , from the vivarium of the Federal University of São Paulo and kept under controlled conditions were used . All experimental procedures were evaluated from Nove University Ethics Committee , and is in accordance with the standards of the Brazilian College of Animal Experimentation - COBEA and patterns of animal experimentation of the International Council for Laboratory Animal Science . The animals were randomly divided into 5 groups: elderly control (GIC) - Not received irradiation to the LBP and has not practiced the workout . Young control group (GJC) - Not received irradiation to the LBP and has not practiced the workout Elderly laser (GIL) Group -. Received irradiation to the LBP and has not practiced training. Senior Exercise Group (GIE) - Not received irradiation only practiced training . Elderly laser and exercise group (GLE) - received irradiation to the LBP and practiced training. The animals were trained in six weeks with daily swimming for 90 minutes. Were evaluated before the beginning of training treadmill aerobic capacity, maximum oxygen consumption (VO2max) and aerobic functional capacity and that at the end of training all these indices were evaluated for comparison . The low-level laser with the DMC brand power of 100 mW , and the wavelength λ of 808 nm , with an energy of 4 joules energy density of 144 J/cm2 , 40 seconds per time point were used. At the end of the 6 weeks of training, the animals of all groups were euthanized. The gastrocnemius muscle was collected. The test of ANOVA and " post hoc test" the Tukey test was applied. Graph- Pad Software 5.0 was used , adopting a significance level of 5 %. RESULTS: VO2max values were observed for young animals (p ˂ 0.0001). The old laser group associated with exercise was obtained statistical difference between the values before and after interventions. (P ˂ 0.0001). Regarding IL - 6 and TNF - α , group exercises and the elderly and those who received exercise and LBP showed a decrease in the levels of cytokines , with a statistical difference with the control group with age (p ˂ 0.05) . In the analysis of the transverse section of the gastrocnemius muscle was obtained difference between the exercise group and exercise age associated with LBP value (p < 0.001). CONCLUSION: The results suggest that laser therapy when associated with doing aerobic exercise may be a therapeutic approach for the reduction of inflammatory markers (IL-6 and TNF-α) and also has a tendency to improve physical performance aged rats.