Superoxide dismutase mimics improves semen quality during chilled preservation of rabbit spermatozoa

摘要

In rabbit farms, artificial insemination is usually undertaken using semen preserved around 18 degrees C. However, increased reactive oxygen species levels during preservation produce sperm dysfunction. Our aim was to evaluate the effect of adding superoxide dismutase (SOD) antioxidant mimics (Tempo and TempoL) to the extenders of rabbit semen on quality parameters, total lipid peroxidation (LPO) and SOD level. Ejaculates from 12 sexually mature males were diluted with an extender containing 0 (control), 0.5, 1 or 2 mM of Tempo or TempoL, respectively. Semen samples were cooled till 18 degrees C and stored for 0, 6 or 24 h. Sperm motility, velocity parameters, viability, plasma membrane integrity, SOD activity and level of thiobarbituric acid reactive substances (TBARS) were determined. Results showed that, in general, SOD antioxidant mimics significantly improved sperm motility compared to control after 6 and 24 h storage. Moreover, at 24 h, Tempo treatments showed motility rates higher than 80% whilst the control group showed the lowest motility rate among all treatments (58.5%, P 0.05). Sperm viability showed no significant differences between treatments at 6 h and 24 h of storage. At 24 h, most SOD antioxidant mimics treatments significantly improved both curvilinear and mean velocity parameters, but only Tempo treatments improved linear velocity parameter. Also, SOD mimics protected sperm cells decreasing TEARS concentration at 6 and 24 h compared to 0 h. In conclusion, the addition of SOD antioxidant mimics during conservation at 18 degrees C and storage of semen until 24 h reduces lipid peroxidation and preserves rabbit semen quality.