Fertilization and early embryology: The effect of pentoxifylline on mouse in-vitro fertilization and early embryonic development

This study was designed to assess the effect of pentoxifylline(PTX) on fertilization and early embryonic development in themouse. Oocytes from superovulated B6CBA female mice were inseminatedin vitro with spermatozoa from B6CBA males incubated with PTXaccording to different protocols, i.e. (i) 3.6 and 7.2 mM PTXwashed out prior to insemination, (ii) 3.6 and 7.2 mM PTX dilutedsix times in the insemination medium and (iii) PTX present at3.6 and 7.2 mM in the insemination medium. After inseminationand washing, fertilization was assessed by the presence of 2-cellstage embryos. These were further cultured up to the blastocystor egg-cylinder stage to asses embryonic development. Parthenogeneticactivation was evaluated by exposing post-ovulatory oocytesto 3.6 and 7.2 mM PTX. If spermatozoa were washed free fromPTX before insemination, no effect on either fertilization orsubsequent development was found. If PTX was not washed out,fertilization was reduced significantly, yet development offertilized oocytes was unaffected. If insemination was performedin the presence of PTX both fertilization and development wereimpaired. Parthenogenetic activation was not increased by PTXexposure. We conclude that if used in in-vitro fertilization,exposure of oocytes and/or zygotes to PTX has to be avoidedby washing out the compound thoroughly to prevent adverse effectson early embryonic development.