Cadmium Interaction with Essential Metals (Zn, Cu, Fe), Metabolism Metallothionein, and Ceruloplasmin in Pregnant Rats and Fetuses

Cadmium administered to rats per os is accumulated in the duodenal mucosa in the form of metallothionein (MT). Therefore, this toxic metal can influence the efficiency of essential metal absorption, especially their concentration in the maternal organism, which plays an essential role during fetal development. The aim of this study is to elucidate the mechanism of the origin of Zn, Cu, and Fe deficiency in fetal rat livers after maternal exposure to cadmium in drinking water and to investigate the roles of MT and ceruloplasmin (Cp) in this phenomenon. Cadmium was given to pregnant dams exposed for 0–20 days of gestation in drinking water at concentrations of 6.25–100 μg Cd/ml. After cessation of exposure, at the lowest dose, a decrease in Cu and Fe concentrations in the duodenal mucosa was found. Simultaneously, diminution in concentration of two cited metals and Cp activity in serum of dam blood was noted. The lowest dose of cadmium developed a drop tendency in microsomal fetal liver iron. Significant correlations were observed between fetal liver Cu contents and Cp activity in serum of dams and Cu concentrations in serum of dams. Diminished Cp activity in serum of dams is related to reduced availability of Cu and Fe in fetuses. In conclusion, it is suggested that the mechanism of Cu and Fe deficit content in fetuses is based on the diminution of absorption of these metals by dam intestines exposed to cadmium on the reduction of metal concentrations in blood serum and, in consequence, their decreasing availability in fetuses.