Inhibition of in vitro fertilization and early embryonic development in hamsters by gossypol

We have previously reported an inhibitory effect of gossypol and its metabolite on bovine and mouse early embryonic development. In the present study, eggs were collected from oviducts of superovulated hamsters. Epididymal sperm were used for in vitro fertilization (IVF). Gossypol at 5, 10, and 30 micrograms/ml significantly inhibited the formation of 2 pronuclei by 45, 65 and 95%, respectively. On the first day of pregnancy, hamsters were given an intrauterine treatment of 200 micrograms of gossypol in 100 microliters of corn oil per uterine horn. On day 3, embryos from controls were in morula (65%) and early morula (17%) stages, while less than 2% of embryos from the gossypol-treated hamsters were in the morula stage. The numbers of embryo implantation sites on day 8 and pups in controls (14 +/- 2.0 and 12 +/- 1.5, respectively) were significantly higher than those in the gossypol-treated hamsters (8.5 +/- 2.0 and 4.0 +/- 1.5, respectively). Our results suggest that gossypol is able to affect fertilization, embryonic development, embryo implantation, and the number of pups in hamsters through a not-yet-defined mechanism.