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 the mouse. Oocytes from superovulated B6CBA female mice were inseminated in vitro with spermatozoa from B6CBA males incubated with PTX according to different protocols, i.e. (i) 3.6 and 7.2 mM PTX washed out prior to insemination, (ii) 3.6 and 7.2 mM PTX diluted six times in the insemination medium and (iii) PTX present at 3.6 and 7.2 mM in the insemination medium. After insemination and washing, fertilization was assessed by the presence of 2-cell stage embryos. These were further cultured up to the blastocyst or egg-cylinder stage to assess embryonic development. Parthenogenetic activation was evaluated by exposing post-ovulatory oocytes to 3.6 and 7.2 mM PTX. If spermatozoa were washed free from PTX before insemination, no effect on either fertilization or subsequent development was found. If PTX was not washed out, fertilization was reduced significantly, yet development of fertilized oocytes was unaffected. If insemination was performed in the presence of PTX both fertilization and development were impaired. Parthenogenetic activation was not increased by PTX exposure. We conclude that if used in in-vitro fertilization, exposure of oocytes and/or zygotes to PTX has to be avoided by washing out the compound thoroughly to prevent adverse effects on early embryonic development.