Effect of Extender Supplementation with Low-molecular-weight Antioxidants on Selected Quality Parameters of Cryopreserved Canine Spermatozoa.

Introduction: The addition of low-molecular-weight antioxidants during the freezing process improves post-thaw sperm quality. The high antioxidant potential of cryopreserved semen could have a positive effect on the motility, viability, and energy status of sperm cells and their ability to bind to the zona pellucida of oocytes. The aim of the study was to determine the effects of different concentrations and combinations of vitamins E and C in a semen extender on selected quality parameters of frozen-thawed canine spermatozoa. Material and Methods: The experimental material was the semen of four mixed-breed dogs. Sperm viability (motility, plasma membrane integrity, and mitochondrial function) was examined at 0, 60, and 120 min in semen samples supplemented with the extender and in the controls. Results: Combined supplementation with vitamins C + E at a concentration of 200 + 200 mu M/1 X 10(9) spermatozoa had the most profound effect on total sperm motility, linear motility, and the percentage of spermatozoa with intact plasma membrane and active mitochondria. Conclusion: The synergistic activity of vitamins E and C had a more beneficial influence on the quality of frozen-thawed sperm than these non-enzymatic antioxidants applied separately.