The fate of Cd, Cu, Ca, Zn, and Fe in rat during the recovery period following cessation of repeated exposure to Cd.

Cadmium was administered subcutaneously to male Wistar rats, 0.1 mL/rat in 0.9% saline 3 times a wk for 4 wk at 3 mg Cd/kg. Saline was administered to control animals in an equivalent manner, without Cd. After the end of the dosing period, the distribution and excretion of Cd, Cu, Ca, Zn, and Fe were observed in some organs and excreta for 35 d (1, 7, 14, 21, 28, and 35 d). Cadmium dosing caused significant disturbances in the metabolism of Zn, Cu, Fe, and Ca, especially during the recovery period. Growth in Cd-dosed animals did not accelerate, even after 5 wk of recovery. There was evidence of mobilization of some elements among organs. Accumulation of Cd occurred in liver, kidney, and spleen during dosing, and during the recovery period it was retained in kidney and testes (for 2 wk) and cleared steadily in liver and RBC (for 5 wk), but increased in spleen (first 3 wk). The pattern of Cd excretion was closely associated with the binding of Cd with metallothioneins in kidney and liver for the first 21 and 7 d, respectively. This was associated with the excretion of Cd-metallothioneins (Cd-MT) in urine from d 1 to 21 during recovery. Cadmium caused higher Ca accumulations in testes and liver, which were probably associated with the lesions observed in these organs. Significant increases of Cu (in kidney d 7) and Fe (in liver) were observed during recovery. Furthermore, significant reductions of Cu and Fe were found in plasma, spleen, and RBC (after 5 wk) and kidney, spleen, and testes (on d 7), and blood (after 5 wk).