Effect of dietary selenium deficiency on the in vitro fertilizing ability of mice spermatozoa
Selenium is an essential micronutrient formammals, being integral part of antioxidant system.The aim of the study was to evaluate the effect ofselenium deficiency on in vitro fertilization (IVF)capacity of spermatozoa and on oxidative stress inthese cells. Male C57BL/6N mice were maintained onselenium-deficient or selenium-sufficient diets (0.02or 0.2 ppm of selenium as selenomethionine, respectively)for 4 months. Liver glutathione peroxidaseactivity measurements were used to confirm seleniumdeficiency. Sperm quality and IVF capability amongboth groups were evaluated. To assess oxidativedamage, lipid peroxidation as malondialdehyde productionwas determined in spermatozoa as well as thetestes. Ultrastructural analyses of spermatozoa nucleiusing transmission electron microscopy were alsoperformed. The percentage of eggs fertilized withsperm from selenium-deficient mice was significantlydecreased by approximately 67%. This reducedfertilization capacity was accompanied by increasedlevels of lipid peroxidation in both the testes andsperm, indicating that selenium deficiency inducedoxidative stress. Consistent with this finding, spermatozoafrom selenium-deficient animals exhibitedaltered chromatin condensation. Deficiency in dietaryselenium decreases the reproductive potential of malemice and is associated with oxidative damage inspermatozoa.