Cadmium: placental mechanisms of fetal toxicity.

摘要: Subcutaneous injections of 40 mumol/kg CdCl2 given to rats on day 18 pregnancy produced a high incidence fetal death and placental necrosis. Fetuses directly injected with in utero were resistant cadmium levels far excess associated following maternal injection. Thus cadmium-induced was not the result direct effect fetus. Similarly, exposure fetuses or dams Cd-metallothionein did produce death. Placental histological changes accumulations suggested mechanisms for toxicity. Histological observed as early 12 hours after injection characteristic local circulatory responses. Blood flow measurements radiolabelled microspheres indicated that uteroplacental blood decreased per cent 75 at 12-16 18-24 Studies initial responses placenta revealed biochemical ultrastructural could be prior alterations No uterine vascular endothelium. effects but may heavy metal. A proposed mechanism induction is trophoblastic damage which leads response injured tissues decrease flow. It nutrient oxygen transport fetus results from ultimately induce