PENTOXIFYLLINE IMPROVES SPERM CAPACITATION AND IN-VITRO FERTILIZATIONOF OOCYTES IN THE GOLDEN-HAMSTER

Pentoxifylline (PF) is used to improve motility of spermatozoa from su bfertile or nonfertile males to accomplish in vitro fertilization in h umans. The possible adverse effect of PF on pre- and peri- implantatio n stage embryo development in a suitable rodent model, such as the gol den hamster, is yet to be determined. In this study, hamster cauda epi didymal spermatozoa were exposed to different concentrations (0.23 to 3.6 mM) of PF, and their quantitative [percentage of motility] and qua litative [Score 0 to 5] motility were assessed and values expressed as the sperm motility index. Upon addition of spermatozoa to dishes cont aining PF, an immediate increase in sperm motility and sperm motility index was evident, which increased up to 4 to 6 h and then declined. T he sperm motility index increase by PF was dose-dependant, and greater than or equal to 1.8 mM PF was detrimental after 4 h. The optimum dos e of PF was found to be 0.45 mM. To assess the fertilizing ability of PF-treated spermatozoa, in vitro fertilization was carried out. Fertil ization rates for spermatozoa treated with 3.6 mM PF were lower (53.8 +/- 7.8) than for the controls (69.5 +/- 10.2), whereas, treatment wit h 0.45 mM PF increased the rates (91.6 +/- 4.3) compared with that of the controls (80.2 +/- 5.9). In conclusion, low concentrations (0.23 t o 0.45 mM) of PF improve sperm capacitation and fertilization of oocyt es in vitro in the golden hamster.