In vitro fertilization after in vivo treatment of rats with three reproductive toxicants

One objective of these experiments was to establish a sensitive assay to ev aluate fertilizing potential of rat gametes in vitro. A second objective wa s to evaluate this in vitro fertilization (TVF) assay as a method to detect in vivo effects of reproductive toxicants on male and female gametes using three known reproductive toxicants as model systems. The IVF assay with zo na-free oocytes was more precise than the assay with cumulus-intact oocytes in these studies (coefficients of variation of 8.7 and 14.4%, respectively ). Sperm fertilizing potential for zona-free oocytes was reduced by treatme nt of rats with m-dinitrobenzene (10-10 000 mu g/kg) and ethylene glycol mo nomethyl ether (50-100 mg/kg) that had no effect on sperm motility. Molinat e (60 mg/kg for 5 days) reduced sperm fertilizing potential concurrently wi th reductions in sperm motility. Neither molinate (60 mg/kg for 5 days) nor dinitrobenzene (0.002% in the drinking water for 14 days) administered to females seemed to affect the fertilizability of their oocytes. Ethylene gly col monomethyl ether treatment (0.15-0.25% in the drinking water for 14 day s) reduced the number of ovulated oocytes. IVF is a means to evaluate toxic ant effects on female gametes and demonstrates sperm's ability to interact with the oocyte plasma membrane. (C) 2000 Published by Elsevier Science Inc . All rights reserved.