Aim: Exercise in a hot environment can lead to an increase in core body temperature and heat stress, which is associated with dysfunction of the lungs. The aim of this study was to investigate the effect of selenium supplementation on the expression of M1 and M2 macrophages in the lung tissue of male Wistar rats following a period of exercise in a hot environment. Methods: In this experimental study, 32 male Wistar rats, aged 10 weeks and weighing 200–250 g, were divided into four groups: control, exercise under normal environmental conditions, exercise under heat stress, and exercise under heat stress combined with selenium. Warm environment training was performed for eight weeks (six sessions per week) at 36±1°C and normal environment training at 22-24°C. Selenium was administered as an oral supplement at a specific dose (0.045 g/kg of selenium to feed). At the end of the period, lung tissue was sampled, M1 macrophage and M2 macrophage gene levels were measured by Real-time RT-PCR, and the ratio of M1 to M2 macrophages was examined. The nonparametric Kruskal-Wallis test and Dunn's post hoc test were used to analyze the data at a significance level of p≤0.05.
Results: The present study showed that the ratio of M1 to M2 macrophages in the warm environment exercise group had a significant increase compared to the control group (P=0.0003). The ratio of M1/M2 in the warm environment exercise group had a significant increase compared to the warm environment exercise group with selenium intake (P=0.03).
Conclusion: Exercise in a hot environment can induce heat stress and lung tissue damage. However, selenium supplementation appears to play an effective role in reducing these adverse effects and improving physiological responses.