The use of pentoxifylline to improve motility of cryopreserved equine spermatozoa

Pentoxifylline was evaluated as a method to increase motility of cryopreser ved equine spermatozoa. In a preliminary experiment, pentoxifylline (3.5 mM or 7.0 mM) was added to extended semen that was chilled to 4 degreesC. Mot ility was evaluated at 8-h intervals for 48 h. The addition of 3.5 or 7.0 m M pentoxifylline appeared to increase the motility of chilled spermatozoa c ompared to controls. Based on these results, similar concentrations of pent oxifylline were added to semen either before or after cryopreservation. The addition of pentoxifylline (3.5 or 7.0 mM) to semen before cryopreserva tion significantly (P < 0.001) decreased total and progressive motility com pared to controls. However, the addition of pentoxifylline (3.5 or 7.0 mM) to cryopreserved semen immediately after thawing significantly (P < 0.01) i ncreased total and progressive motility compared to controls. These results indicate that pentoxifylline enhanced the postthaw motility of cryopreserv ed equine semen when added after thawing. Further research is required to e valuate the effect of pentoxifylline on the fertility of cryopreserved equi ne semen. (C) 2000 by Elsevier Science Inc.