Cryoprotective Effect of Molecular Hydrogen

Aim: the effect of cryopreservation and molecular hydrogen (Н2) on the sperm quality characteristics, metabolic, oxidative and antioxidant indices of spermatozoa. Sperm diluted with BioXcell diluent, sperm after cryopreservation and sperm after cryopreservation with Н2 were studied as comparison groups. Qualitative indices of spermatozoa, intensity of free-radical processes, activity of antioxidant enzymes and ATP concentration were measured in all groups. Lipoperoxidation was found to be reduced, and antioxidant activity was increased in sperm after cryopreservation with Н2. It was shown that the content of diene, triene conjugates, malonicdialdehyde decreased in spermatozoa and the activity of superoxidedismutase and catalase increased in sperm after cryopreservation with Н2. Reduction of oxidative processes under the action of Н2 was accompanied by an increase in the concentration of ATP in spermatozoa. After thawing, a significant preservation of spermatozoa motility was recorded under H2 action compared to the group without H2. Thus, H2 is effective in its ability to quench reactive oxygen species and thereby protect spermatozoa from the effects of oxidative stress during cryoconservation. These properties of H2 protect spermatozoa at low temperatures and determine the preservation of high functional activity of spermatozoa after thawing.