Potenciais efeitos da cafeína sobre parâmetros bioquímicos e inflamatórios em ratos submetidos ao treinamento intervalado de alta intensidade

Abstract

Caffeine has been used as ergogenic substance for the purpose of improving athletic performance or attenuating fatigue mechanisms. However, the ergogenic effect of caffeine on high-intensity exercise remains controversial and unclear, others factors such as exercise duration, protocol used, and individuals' training status may interfere in response. Objective of this study was to evaluate the effects of caffeine on biochemical muscle, neurochemical and inflammatory parameters in rats submitted to high-intensity interval training (HIIT). The animals were also divided in six groups: Control group, Caffeine 4 mg, Caffeine 8 mg, HIIT, HIIT + caffeine 4 mg and HIIT + caffeine 8 mg. The rats of groups HIIT, HIIT + 4mg and HIIT + 8mg were trained three times a week for 6 weeks for a total workload 23% of the body weight at the end of the experiment. The exercise protocol (Swimming) was performed three times per week on alternate days (48h of recovery between sessions) always at the same time. Caffeine was administered 30 minutes before training, orally. In muscle was evaluated glycogen levels, enzymes acetylcholinesterase/Ca2+-ATPase activity and histological changes. In CNS was evaluated anxiolytic behavior, enzyme Na+, K+-ATPase activity and oxidative stress parameters. In lymphocytes, was evaluated the effects of caffeine and HIIT on proliferation, cellular immune response to phytohemagglutinin (PHA) and cytokines (IL-06 – IL-10). Our results demonstrated an increase in glycogen levels all groups when compared to control group. HIIT increased thickness in the left ventricle as well as caused an increase in Ca2+-ATPase (67,43%- acute and 34,51% - chronic) activity and decrease in AChE (20,69%) activity in gastrocnemius muscle. Caffeine treatment prevented changes in enzymatic activities, as well as adaptation to left ventricular hypertrophy induced by HIIT. HIIT induced anxiolytic behavior and increased the activity of Na +,K +-ATPase (46,13% cerebral cortex and 50,13% hippocampus) and glutathione peroxidase (38%), TBARS levels (60% - cerebral cortex and 37,66% - hippocampus) and altered the activity of superoxide dismutase and catalase in cerebral cortex, hippocampus and striatum of rats. Caffeine treatment was able to prevent CNS alterations HIIT-induced. In T lymphocytes, caffeine associated to HIIT promoted an increase in T lymphocyte proliferation (147, 61%) and glucocorticoid sensitivity. HIIT induced a decrease in ATP (19,88%) and ADP (31,28%) hydrolysis lymphocytes already caffeine was able to reverse only alterations in the ATP hydrolysis. HIIT caused an increase in ADA (30,27%) and AChE (54,76%) activities in lymphocytes and this effect was pronounced in rats trained and treated with caffeine. IL-6 level (138,5% ) was increased while IL-10 level (41%) was decreased in trained animals (HIIT) and caffeine was able to reverse this effect. Our results demonstrate that caffeine can modulate pathways for muscle contraction in addition to preventing inflammatory, redox state changes induced by HIIT.