Efeitos do exercício físico sobre parâmetros de estresse oxidativo em ratos hipertensos

Abstract

Hypertension has been regarded as one of the most important factors associated with the development of vascular disease and is closely linked to increased reactive oxygen species (ROS). In contrast, exercise has been prescribed as an adjunct in the treatment and/or prevention of this pathology. Considering it, the present work investigated the effects of six weeks of swimming training on blood pressure (BP), nitric oxide (NO) levels and oxidative stress parameters such as protein and lipid oxidation, antioxidant enzyme activity and endogenous non-enzymatic antioxidant content in kidney and blood, as well as on serum biochemical parameters (cholesterol, tryclicerides, urea and creatinine) from L-NAME-induced hypertension treated rats. Animals were divided into four groups (n= 10): Control, Exercise, L-NAME and Exercise L-NAME. After 60 days of treatment, the animals were sacrificed and total blood, serum, plasma and kidney were used for experimental determinations. The results showed that hypertension provided a reduction in the levels of NO, changes in cholesterol, triglycerides, urea and creatinine, and induced an increase on oxidative stress, observed by the reduction of enzymatic (superoxide dismutase and catalase) and non-enzymatic (non-protein thiol content and ascorbic acid) antioxidant defenses and increased on protein oxidation and lipid peroxidation. The moderate aerobic exercise showed hypotensive effect, reducing BP in L-NAMEtreated rats, probably by maintaining the levels of NO. In addition, physical training was able to prevent kidney damage and changes in lipid profile of hypertensive rats as well as prevent oxidative damage, verified by the levels of lipid and protein oxidation, which remained at levels close to those found in normotensive rats. Exercise also prevented changes in enzymatic and non enzymatic antioxidant defenses, which highlight its effects as an antioxidant. Based on these results, we conclude that moderate aerobic exercise can play a key role in acting as an adjunct in the treatment of hypertension.