In this study, it was aimed to investigate the effect of important antioxidant, selenium, on swimming time, oxidative stress, and oxidative stress-related HO-1 and Nrf2 protein levels in rats that swam until depleted. For this purpose, 18 male Wistar-Albino rats were divided into 2 groups, 9 in each group. Before the experiment, the groups were swam for half an hour for rats to get used to swimming.

Placebo (physiological saline) was administered to the control group, and 0.8 mg/kg/day selenium was administered intraperitoneally to the selenium group for 20 days. At the end of the 20th day, the groups were swam and the swimming times were recorded. Rats were sacrificed under anesthesia immediately after swimming. Malondialdehyde (MDA), glutathione (GSH) levels, catalase and glutathione peroxidase (GSH-Px) enzyme activities were determined in blood, muscle and liver tissue samples. HO-1 and Nrf2 protein levels in muscle and liver tissue were analyzed by Western blot technique. According to the data; there was no difference between the groups in terms of swimming time (P>0.05). Liver and muscle MDA levels were found to be significantly lower in the selenium group (P<0.05). There was a significant increase in liver GSH level in the selenium group (P<0.05). In muscle, plasma and liver, GSH-Px levels significantly increased in the selenium group (P<0.05). Liver HO-1 and Nrf2 protein expression levels were significantly higher in the selenium group (P<0.01).

In conclusion, selenium treatment resulted in a decrease in the oxidative stress and an increase in the antioxidant activity and Nrf2 and HO-1 protein expression levels in the rats that swam until exhaustion, but did not affect swimming times.