Age-dependent accumulation of cadmium in rats exposed to contaminated drinking water; interactions with zinc and copper and subcellular Cd distribution in kidney cells.

One of each pair of female sister rats aging 1, 4, 7 or 10 months was exposed during 3 months to 31.5 mg/L Cd (as CdCl2) in its drinking water and sacrificed immediately after Cd exposure together with its untreated sister. Concentrations of Cd, Zn and Cu were measured in the kidneys (medulla and cortex), the liver, the duodenum and the uterus. Furthermore, the subcellular distribution of Cd was measured in renal tissue. The accumulation of metal ions, defined as the difference between Cd-treated and untreated rats, was pronounced in all tissues except the uterus and was significantly decreased at increasing age. Multivariate analysis of variance revealed significant interaction with Zn and Cu. Higher Cd accumulation in the tissues of young animals probably depends on the higher consumption of contaminated drinking water per kilogram of body weight. High concentrations of Cd detected in cell nuclei may be due to the similarity between Cd2+ and Ca2+.