Toxicité à long terme du cadmium administré à très faible dose chez le rat: Répartition du cadmium,du zinc,et du cuivre

Urinary cadmium elimination and tissue distribution as well as that of zinc and copper were studied in groups of rats receiving 0 or 2.5 ppm Cd in water for 3, 6, or 12 months. By 3 months, cadmium ingestion induced only increases in urinary and kidney cadmium concentrations, after which urinary cadmium remained stable as a reflection of daily food intake. On the other hand, kidney cadmium accumulated reflecting total cadmium ingestion. In the livers and kidneys of animals observed during 3 and 6 months, cadmium accumulation was more marked in females, whether receiving cadmium or not. In other organs (liver, pancreas, ovary, testicle) cadmium concentrations were not higher in animals receiving cadmium. Kidney fixation of cadmium was associated with a slight decrease of hepatic copper after 3 months and a decrease in zinc as well after 12 months. These results attest that cadmium ingested at very low doses selectively accumulates in the kidney. They suggest either a mechanism unrelated to metallothionein synthesis or an early kidney induction.