Effects of Hydrazine on Pregnant ICR Mice

摘要

As more women enter jobs formerly held by men there is a risk that exposure to some chemicals may cause birth defects in an unborn child. The objective of this project was to determine the usefulness of ICR Mice as a test species. Hydrazine was injected intraperitoneally on days 6, 7, 8, and 9 of gestation at concentrations to 4, 12, 20, 30, and 40 mg/kg body weight. Physiological saline was administered in the same manner to a control group. Hydrazine in concentrations up to 20 mg/kg body weight had no significant effect on the number of implantations per female, the mean number of viable fetuses per litter, or the mean number of resorptions per litter. At concentrations of 30 and 40 mg/kg, hydrazine was fetotoxic and 4 of 21 females died at a concentration of 40 mg/kg. As the dose was increased from 4 to 30 mg/kg there was an increasing percentage of litters with soft tissue anomalies with exencephaly and hydronephrosis produced most often. Skeletal abnormalities were produced at a higher frequency and at lower concentrations than soft tissue abnormalities. Supernumerary ribs accounted for most of these defects. Pregnant mice receiving 12 and 20 mg/kg showed a lower rate of weight gain during the injection period than those receiving saline or 4 mg/kg. After the injection period, from days 9 through 11, the mice receiving 12 and 20 mg/kg had the highest rate of gain.