Effect of cadmium pretreatment on teratogenicity and fetolethality of cadmium.

Pretreatment with cadmium is reported to protect animals, to some extent, from acute toxicity of a following administration of a higher dose of cadmium itself. On the other hand, it is still unknown as to whether or not the teratogenicity and/or the fetolethality of cadmium are reduced by such pretreatment with cadmium. Based on Cadmium Pretreatment and Fetotoxicity of Cadmium 287 a report that administrations of cadmium sulfate to pregnant mice on their 7th day of gestation caused exencephaly and death of their fetuses, the authors investigated possible prevention of teratogenic and fetolethal effects of cadmium by pretreatment with a smaller dose of cadmium. On day 6 of gestation, a low dose (0.5 mg/kg or 1 mg/kg) of cadmium fulfate was administered intraperitoneally (ip) or subcutaneously (sc) to pregnant JCL : ICR mice, and on the next day a high dose (5 mg/kg) of the same compound was administered ip. Dams were sacrificed on day 17 of gestation and con.ceptuses were examined. A dose of 0.5 mg/kg of cadmium ip failed to show a protective effect against teratogenicity, but 1 mg/kg sc or 1 mg/kg ip was effective. However, induction of exencephaly was not completely blocked by these pretreatments. On the other hand, the protective effect against fetolethality was remarkable and fetal death rates were significantly lowered by overall pretreatment to control values.