Foetotoxicity of Cadmium in Quackenbush Strain Mice and the Effects of the Metal on Uterine Alkaline Phosphatase During Pseudopregnancy

Abstract

Experiments were conducted to determine the sensitivity of Quackenbush strain (QS) mice to the foetotoxic effects of single subcutaneous injections of CdClz (2, 4 and 8 mg of cadmium per kilogram body weight) on days 1, 2, 4 or 8 of pregnancy. Autopsies performed on day 16 of pregnancy revealed that cadmium was teratogenic and increased the incidence of malformed forelimbs and exencephaly and decreased foetal weight. The metal caused foetal weight changes and exencephaly only when it was administered on day 8 of pregnancy indicating that the post-implantation stage presents the QS mouse with a period of increased sensitivity to the foetotoxic effects of cadmium.Although injections of cadmium (8 mg per kilogram body weight) during early pseudopregnancy did not prevent the uterus from undergoing a decidual reaction in response to a peanut oil stimulus, they did in some cases prevent alkaline phosphatase from reaching maximal activity levels in decidualized uterine horns. Thus, inhibition of alkaline phosphatase occurred only in response to the metal injected on day 4 of pseudopregnancy and the enzyme was not affected when cadmium was administered on days 1,2, 3, 5 or 6 of pseudopregnancy.The results suggested that changes in either progesterone and oestrogen production by the ovary or the alkaline phosphatase activity of the uterus are unlikely to be responsible to any great extent for the teratogenic effects of single subcutaneous injections of cadmium in the QS mouse during early pregnancy.