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Abstract

Generation of reactive oxygen species (ROS) is a normal process in the life of aerobic organisms. Under physiological conditions, these deleterious species are mostly removed by the cellular antioxidant systems, which include antioxidant vitamins, protein and non-protein thiols, and antioxidant enzymes. Since the antioxidant reserve capacity in most tissues is rather marginal, strenuous physical exercise characterized by a remarkable increase in oxygen consumption with concomitant production of ROS presents a challenge to the antioxidant systems. An acute bout of exercise at sufficient intensity has been shown to stimulate activities of antioxidant enzymes. This could be considered as a defensive mechanism of the cell under oxidative stress. However, prolonged heavy exercise may cause a transient reduction of tissue vitamin E content and a change of glutathione redox status in various body tissues. Deficiency of antioxidant nutrients appears to hamper antioxidant systems and augment exercise-induced oxidative stress and tissue damage. Chronic exercise training seems to induce activities of antioxidant enzymes and perhaps stimulate GSH levels in body fluids. Recent research suggest that supplementation of certain antioxidant nutrients are necessary for physically active individuals.

Effect of Vitamin C Supplementation on Lipid Peroxidation and Lactate Levels in Individuals Performing Exhaustion Exercise

“…Levels of antioxidants are known to vary depending on the intensity, type and length of exercise (23). However, it was reported that the activity of antioxidant enzymes like SOD and catalase in the blood and tissues increased after acute exercise (24). Exercise may be increase the antioxidant defense in general.…”

Epigenetic regulation of pulmonary arterial hypertension

“…34,35,[41][42][43][44] As a non-protein thiol source in mammalian cells, the tripeptide glutathione system has an key role in the maintenance of cellular redox status, and especially important for cellular defense against ROS. 45,46 Glutathione can directly scavenge free radicals in non-enzymatic reactions, and reduce hydrogen peroxide via a reaction catalyzed by the glutathione peroxidases. 46,47 Previous studies have revealed that glutathione deficiency are closely associated with ROS production.…”

“…45,46 Glutathione can directly scavenge free radicals in non-enzymatic reactions, and reduce hydrogen peroxide via a reaction catalyzed by the glutathione peroxidases. 46,47 Previous studies have revealed that glutathione deficiency are closely associated with ROS production. 45,48 SOD is one of the main ROS enzymatic scavengers, catalyzing the dismutation of superoxide into H 2 O 2 and O 2 , and having an important role in vascular tone, lung function and metabolism of NO.…”

Exercise-induced changes in renal URAT1 activity and expression in rats

“…Regarding the elevated reactive oxygen species (ROS) and urate generation during physical activity, [9][10][14][15][16] urate recirculation in the PT cells seems quite logical and may have some physiological importance in preventing hazardous effects of ROS and maintaining the integrity of the PT cells. Therefore, reduced urate reabsorption or excretion may deteriorate the maintenance of the normal uric acid homeostasis in exercisers.…”