Effects of exercise in thermal climates on human renal function and its mechanism of oxidative stress / 解放军医学杂志

ABSTRACT

Objective: To investigate the effect of exercise in thermal climates on the renal functions and explore the role of oxidative stress injury in the pathogenesis of exertional heat stroke (EHS). Methods: Totally 187 young soldiers in the subtropical area of Southeast China were divided randomly into two groups. All subjects underwent 1.5km, 3km and 5km cross-country running under two different environmental conditions normal temperature and normal humidity [temperature (26 ± 2) °C, humidity 50% ± 5%]; high temperature and high humidity [temperature (33 ± 2) °C, humidity 65% ± 5%], and each soldiers' blood samples were taken at pre and post running. The level of Cr, BUN, CK, CK-MB, LDH and SOD were measured by automatic biochemical analyzer. The levels of serum 8-OHdG was detected by enzyme-linked immunosorbent assay (ELISA). Results: 1) After exercise, the Cr and BUN of the two groups increased, compared with the pre-exercise the differences were significant (P<0.05). As the amount of exercise increase, the level of Cr and BUN will be further elevated, and compared with 1.5 km cross-country running respectively, there were significant differences in 3.0 km and 5.0 km cross-country running (P<0.05). The level of Cr and BUN were significantly higher in the high-temperature and high-humidity group than those in the normal temperature and normal humidity group (P<0.05); 2) After exercise, the CK, CK-MB and LDH of the two groups increased, compared with the pre-exercise the differences were significant (P<0.05). As the amount of exercise increase, the level of CK, CK-MB and LDH will be further elevated, and compared with 1.5 km cross-country running respectively, there were significant differences in 3.0 km and 5.0 km cross-country running (P<0.05). After 5.0 km cross-country running, the level of Cr and BUN were significantly higher in the high-temperature and high-humidity group than those in the normal temperature and normal humidity group (P<0.05); 3) After exercise, the level of 8-OHdG increased and the level of SOD decreased in the two groups, compared with the pre-exercise the differences were significant (P<0.05). As the amount of exercise increase, the level of 8-OHdG increased significantly and the level of SOD decreased significantly, and compared with 1.5 km cross-country running respectively, there were significant differences in 3.0 km and 5.0 km cross-country running (P<0.05). After 5.0 km cross-country running, the level of 8-OHdG were significantly higher and the level of SOD were significantly lower in the high-temperature and high-humidity group than those in the normal temperature and normal humidity group (P<0.05). Conclusion: Long time strenuous exercise under the condition of high temperature and high humidity can easily induce heat stress damage. The muscle and renal are vulnerable to heat stress damage. Oxidative stress injury may play an important role in heat stress damage of renal.