This study was carried out to identify the cytogenic effects of cadmium and lead in pregnant mouse. The mice were divided into three cadmium treatment groups, three lead treatment groups and two control groups- a negative control group and a positive control group treated with benzo(a)pyrene.
Cadmium chloride was injected in the amount of 1mg/kg, 2mg/kg, 4mg/kg and lead acetate 20mg/kg, 40mg/kg, 80mg/kg in separate groups into peritoneal eavity at the 16th day of gestation.
Twenty hours after injection the liver of fetus was extracted, and polychromatic erythrocyte(PCE) and micronucleated polychromatic erythrocyte(MNPCE) were observed in hepatic tissues. The appearance rate of the MNPCE was calculated by the ratio of MNPCE to PCE.
The results obtained are as follows:
1. The appearance rate of MNPCE in the 1mg/kg cadmium treatment group was similar to that of the control group. As for the 2mg/kg treatment group, the rate´ was 0.44+0.20 %, which was about three times as high as that of the control group. In the case of the 4mg/kg cadmium treatment group, al though the two mice were maintaining the original shape of their fetuses, the size of the fetus was reduced to mere half. The livers were so much decomposed that it was impossible to examine the cytogenic effects.
2. The appearance rate of MNPCE in the 20mg/kg lead treatment group was 0.46+0.15 o°(P<0.05). Whereas in the 40mg/kg treatment groups the rate was 0.78+0.13%(P<0.05), which was about 5.6 times as high as that of control group. As for the 80mg/kg lead treatment group, the rate was 0.17-0.06%, which was similar to that of control group. It was due to the difficulty of measuring the MNPCE with few PCE.
|