P-92: An Experiment on Osmotic Behavior of The Goat Epididymal Sperm Following Exposure to Different Cryoprotectants above Zero Temaperature

cell in biological studies. The studies showed the good response of human sperm to cryobiologic assays. However, in farm animals because of different composition of the cell membrane and presence of more unsaturated fatty acid make sperm more sensitive to oxidative stress that is one the most important factors that can affect the sperm viability during cryopreservation. The aim of the present study was to find the effects of different cryoprotectants on the goat epididymal sperm total motility. Materials and Methods: The goat testes-epididymides were collected (6 pairs) and epididymal sperm retrieved in warmed TALP (5 mL) for 15 minutes. The sperm suspension was homogenized and 200 μL was overlaid with TALP within 1.5 mL Eppendorph micro-tube and left in room temperature (25-33 C) for 30-45 minutes. The swimmed-up sperm were collected from upper layer of micro-tube. Suspension of sperm adjusted with concentration of 20×106 sperm /mL with different cryoprotectant. The cryoprotectant solutions were provided in double distilled water (DW) or TALP. The solution composed of Ethylene glycol (EG 1 and 5 %), Glycerol (Gly 1%) and different molarities of sucrose (0, 0.2, 0.4 and 0.6 M). The combinations of EG2.5 and Gly2.5 with 0.2 M sucrose also were considered. A combination of EG5 with 0.4 M sucrose was assessed, too. After 7-10 minutes of exposure, total motility of sperm was evaluated on a warmed slide under cover-slip. The proportion of total estimated motility after exposure to before exposure was calculated and analyzed using GLM procedure in SAS. Results: The results showed that basic medium for cryoprotectant can be DW (54.7 ± 4.52) or TALP (49.7 ± 6.52 %) with no significant difference (p=0.53). A linear negative tendency between sucrose osmolaity and sperm motility was detected; after 10 min exposure in sucrose alone no motile sperm was seen. After 7 min exposure, the rates of estimated motile sperm were the highest in solutions composed of EG2.5+S0.2, Gly2.5+S0.2 and S0.2 alone. The highest concentration of EG, 5%, with (43.3 ± 11.2) or without (30 ± 11.2) S (0.4 M) significantly decreased rate of total sperm motility. The highest concentration of sucrose stopped motile sperm during assay (0%). Conclusion: The results of the present study showed a linear toxic effect of sucrose on goat epididymal sperm and also showed that incorporation of the permeable cryoprotectants with low levels of sucrose can be an option for diluting epididymal sperm for above zero temperature.