Micromolar concentration of pentoxifylline improves development in vitro of hamster 8-cell embryos: confirmation of biological viability by embryo transfer.

The influence of the sperm motility stimulant pentoxifylline (PF) on preimplantation embryo development in hamsters was evaluated. Eight-cell embryos were cultured in hamster embryo culture medium (HECM)-2, with or without PF (0.023-3.6 mM). There was 90%, 37% and 29% inhibition of blastocyst development by 3.6 (used for human sperm), 0.9 and 0.45 mM PF, respectively. However, 23 microM PF (exposed to hamster oocytes during IVF) significantly (P < 0.05) improved blastocyst development (63.6% v. 51.8%); morulae development was, however, not curtailed by 0.45 mM or 0.9 mM PF (51.8%+/-6.0 or 50.5%+/-11.3, respectively). Post-implantation viability of PF-treated embryos was assessed by embryo transfer; 43% of 80 PF-treated embryos implanted compared with 40% of 79 control embryos. Of the 9 recipients, 6 females delivered pups (19, i.e. 16% of transferred embryos or 53% of implanted embryos). These data show that in hamsters, continuous presence of PF at 0.45-3.6 mM is detrimental to 8-cell embryo development whereas 23 microM PF improves the development of embryos to viable blastocysts which produce live offspring.