抄録
Sodium nitrite (NaNO2) was administered to pregnant mice during the critical period (from 6th the day to the 15th day of gestation) of the organogenesis in fetuses to examine the teratogenic effects of the food additive (color fixative) NaNO2. The dosages of NaNO2 employed in this experiment were 20, 40, 80 and 120mg/kg/day.
On the 17th day of gestation, fetuses were removed by Caesarean section in order to examine their body weights, external malformations and skeletal.
The results obtained can be summarized as follows;
1) Significant suppression of the body weight of pregnant mice was observed in the 80-and 120mg/ kg/day exposed-groups.
2) In the group of pregnant mice exposed to 120mg/kg, the numbers of implantations and living fetuses, along with the litter size, were significantly decresed as compared with those of the control group.
3) Cleft palate was observed sporadically in the exposed NaNO2 groups. However, the incidence was not significant as compared with the frequency observed in the control group.
4) Fetuses with a 14th rib were observed in exposed groups. However, this was considered to be within the spontaneous incidence of ICR mice.
5) Suppression of body weight gain was observed in the offspring of the group exposed to 120mg/kg/ day for the first 14 days. However, retardation was recovered from at 7 weeks of age.
