RESUMEN
To investigate the ameliorative potential of sodium selenite and zinc sulfate on intensive-swimming-induced testicular disorders, 48 Wistar male rats (age, 4 months; mass, 146.2 +/- 3.6 g) were randomly divided into 4 groups: the unexercised-control group (n = 12); the exercised group (n = 12); the control supplemented group (n = 12); and the exercised supplemented group (n = 12). For 10 weeks, the exercised rats underwent a protocol that consisted of 4 h.d-1 swimming, for 6 d.week-1; the control rats did not exercise. For 10 weeks, both the supplemented groups received an oral daily dose of a combination of sodium selenite and zinc sulfate (6 and 3 mg.kg body mass-1, respectively). After 10 weeks, a significant reduction (p < 0.05) was seen in rats in the exercised group, compared with rats in both control groups, in paired testicular masses; in epididymal sperm count; in testicular Delta5, 3beta-hydroxysteroid dehydrogenase (HSD) and 17beta-HSD; in plasma levels of testosterone, luteinizing hormone, follicle-stimulating hormone, and prolactin; in the numbers of preleptotine spermatocytes, midpachytene spermatocytes, and stage 7 spermatids of the stage VII seminiferous epithelium cycle; and in fertility performance. As well, a significant increase (p < 0.05) was seen in the exercised group, compared with both control groups, in plasma corticosterone levels and in testicular content of malondialdehyde and catalase activity. At the same time, there was a significant reduction (p < 0.05) in the exercised group, compared with both control groups, in plasma concentrations of zinc and selenium; in the testicular content of glutathione (GSH), the glutathione and glutathione disulphide (GSSG) ratio, ascorbic acid, and alpha-tocopherol; and in testicular activities of superoxide dismutase, glutathione-peroxidase, and glutathione-S-transferase in the testes. No significant changes were seen in the number of spermatogonia-A from the stage VII seminiferous epithelium cycle or the testicular content of GSSG among the groups. Sodium selenite and zinc sulfate supplementation significantly protected against exercise-induced testicular gamatogenic and spermatogenic disorders, prevented testicular oxidative stress, and increased antioxidant status. It can be concluded that intensive-swimming-induced oxidative stress causes dysfunctions in the male reproductive system, which can be protected by the coadministration of sodium selenite and zinc sulfate.