||Use of the Fungicide Carbendazim as a Model Compound to Determine the Impact of Acute Chemical Exposure during Oocyte Maturation and Fertilization on Pregnancy Outcome in the Hamster.
Perreault, S. D. ;
Jeffay, S. ;
Poss, P. ;
Laskey, J. W. ;
||ManTech Environmental Technology, Inc., Research Triangle Park, NC.;Health Effects Research Lab., Research Triangle Park, NC. Reproductive Toxicology Branch.
Animal pregnancy ;
Dose-response relationships ;
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The fungicide MBC is a microtubule poison. The authors hypothesized that microtubule-dependent events occurring in the oocyte during meiotic maturation and fertilization may be sensitive to perturbation by MBC such that exposure to MBC during the critical peri- fertilization period would result in early pregnancy loss. Female hamsters were given a single oral dose of MBC during meiosis I or II. Pregnancy outcome was assessed on day 15. When given during meiosis I, MBC treatment reduced the percentage of pregnant hamsters (at 750 or 1000 mg/kg), and the average litter size (250 to 1000 mg/kg). When given during meiosis II, shortly before and during fertilization, MBC treatment (1000 mg/kg) produced a similar decrease in litter size. The effect disappeared when MBC was administered at a slightly later time, after the microtubule- dependent events of fertilization have occurred. These results demonstrate that a single exposure to a microtubule poison such as MBC at critical times, coincident with microtubule-dependent meiotic events, can result in very early pregnancy loss.