Evaluation of the Embryotoxicity of Hydrazine in Rats

Abstract : Hydrazine (Hz) was evaluated for embryotoxic and teratogenic potential in rats. The Pregnant Fischer 344 (F-344) rats were treated with 0, 2. 5, 5.0, and 10.0 mg Hz/kg ip on gestation days 6-15. Dose-related embryolethality and maternal toxicity were observed at the two higher doses. Pregnant F-344 rats were treated with 10.0 mg Hz/kg ip on gestation days 7-9, 10-12, or 13-15. The prenatal period most susceptible to Hz toxicity was days 7- 9. Embryolethality and an increase in the incidence of anomalies, but not major malformations, were observed in this group. Pregnant F-344 rats were percutaneously treated with 0, 5.0, and 50.0 mg Hz/kg on gestation day 9. The higher dose produced a high incidence of embryolethality. Pregnant F-344 rats were treated with 10.0 mg Hz/kg ip on gestation days 7-9. Pups were evaluated for postnatal effects of prenatal Hz treatment. An increase in prenatal mortality was observed, but none of the developmental parameters monitored including weight gain, ear detachment, incisor eruption, eye opening, surface righting, cliff avoidance, forward motion, and swimming ability were adversely affected. The principal toxic effect of prenatal Hz treatment was embryolethality which was observed at doses which produced maternal toxicity.