Effect of pentoxifylline on implantation and post-implantation development of mouse embryos in vitro

Previous work from our laboratory has revealed that brief exposure of mouse zygotes to 3.6 and 7.2 mM pentoxifylline reduced cell numbers in mouse embryos reaching the blastocyst stage in vitro. Since a decrease in cell numbers may impair further development, the present study aimed to assess the implantation in vitro and the development beyond implantation of these embryos. Blastocysts cultured from the one-cell stage in the presence of 5, 10 and 50 microM pentoxifylline, i.e. concentrations expected in the secretions of the genital tract after oral administration, were shown to develop normally to the egg cylinder stage in vitro. Blastocysts, obtained after culture in vitro of zygotes exposed approximately 29 h after human chorionic gonadotrophin (HCG) for 30 min to 3.6 and 7.2 mM pentoxifylline, i.e. the concentrations used for enhancing sperm function in vitro, could implant but their development to the egg cylinder stage was found to be impaired. The same effect was noticed if blastocysts, grown in vitro from the one-cell stage, were exposed to 3.6 and 7.2 mM pentoxifylline for 30 min in vitro approximately 120 h after HCG. These findings imply that when pentoxifylline is used to enhance sperm function in vitro, it should be washed out of the preparation used for insemination.