Moderate aerobic exercise reduces ozone‐produced oxidative stress in rats

Abstract

Nitric oxide (NO) increases as a result of exercise adaptation. Moderate exercise produces oxidative stress (OS) that stimulates endogenous antioxidant capacity. We previously found that ozone (O3) produced OS and endothelial dysfunction in rats. O3 has been related to increased all‐cause mortality in humans, and aerobic exercise reduced this relationship. The goal of this study was to determine if moderate aerobic exercise reduced OS produced by O3. Male Wistar rats (230–250 g, 10‐weeks old, n=12) were trained to swim 90 min daily (14 days). Six of the rats were exposed to O3 (0.5 ppm, 4 h/day) one hour before exercise. Two groups of sedentary rats (n=6, each) were used as control, one of which was exposed to O3. At the end of the experiment blood was taken from the carotid artery and the animals were euthanized. Measurements were made on the plasma. O3 decreased reduced nitrates (indirect measurement of NO) and produced OS manifested by increased plasma malondialdehyde and 8‐isoprostane, and decreased superoxide dismutase (SOD) activity. Exercise significantly blocked O3 effects, although SOD was also decreased by exercise (the greater drop was in the O3 group).ConclusionAerobic exercise protects against OS produced by O3 and the effect is independent of SOD. Future studies will determine if exercise effects remain after long O3 exposure and if other antioxidants are responsible for those effects