Abstract: 227

ADDITION OF SPECIFIC METABOLITES TO BULL EPIDIDYMAL CELL CULTURE MEDIUM ENHANCE SURVIVAL AND MOTILITY OF FROZEN-THAWED BOVINE SPERM.

Marc-Andre Sirard^{1 *}, Carlos Reyes-Moreno¹ , Annie Gagnon¹ , Robert Sullivan^{1 *}
Center of Research in Biology of Reproduction, Laval University, Sainte-Foy, Quebec, Canada. ¹

We have developed a functional epididymal cell culture system that enhances motility of co-incubated bovine sperm. Thus, we have modified a previously described principal cell medium (PCM; Moore et al, Fertil Steril 58:776-83, 1992) to improve this beneficial effect on bovine sperm motility, as well as on the long-term viability of cauda epididymal cell monolayers. Our epididymal-specific cell medium (ECM) was prepared with RPMI-1640 medium, using HEPES as a buffer, and adding myo-inositol, pyruvate, lactate, glycerol and carnitine. Osmolarity of this supplemented medium was 365+5 mOsm, which was similar to the epididymal fluid osmolarity. As expected, ECM was more efficient that PCM to sustain sperm motility. Although spermatozoa motility decrease progressively in both PCM and ECM media, motility of cryopreserved and epididymal spermatozoa are significantly higher after a 3h and 6h incubation period in ECM compared to PCM. After 24h of incubation, spermatozoa were totally immotile whereas epididymal spermatozoa maintained 8% and 39% of motility in PCM and ECM respectively. Cell to cell interactions were studied by co-incubating frozen-thawed spermatozoa with cauda epididymal cells cultured in ECM alone or supplemented with 0.5% BSA or with increasing concentrations of FBS. After 24h of co-incubation, spermatozoa motility decrease in a similar fashion in all experiments (average of 40 ± 3%). After a co-incubation period of 48h, sperm motility was evaluated at 10%, 29%, and 2% from ECM alone, ECM ± 0.5% BSA, and ECM ± 1% FBS respectively. These data suggest that motility and survival of frozen-thawed spermatozoa can be improved using a culture media containing any specific metabolites as detected in epididymal fluid. This work was supported by NSERC-Canada and Cattle Breeding Research Council-Canada.

    This abstract is being presented on Monday, August 2 at 8:00 AM to 10:15 AM at CUB 2nd Floor Ballroom.