Effects of Long-Term Ingestion of Cadmium-Polluted Rice or Low-Dose Cadmium-Supplemented Diet on the Endogenous Copper and Zinc Balance in Female Rats

Abstract

The concentrations of endogenous copper (Cu) and zinc (Zn) in the liver and kidney of female rats were measured after ingestion of cadmium (Cd)-polluted (1.06 ppm) rice or cadmium-supplemented (1.1, 5, 20, and 40 ppm) rice for 12, 18, and 22 months. In the liver, the Cd concentration increases in a dose-dependent manner for the first 18 months. After 18 months, the concentration remained stationary in the low-dose groups, increased in the 5-ppm group, and decreased in the 20- and 40-ppm groups. The Cu concentration was almost unchanged through the experiment, and the Zn concentration increased in a dose-dependent manner. In the kidneys, changes in the Cd concentration resembled that in the liver. The concentrations of Cu increased in a dose-dependent manner at 12 and 18 months. The Zn concentration increased more in the 5-ppm group but not dose dependently.