Effect of cadmium administration and aging on the concentration of essential metals in liver and kidney

To investigate the changes in the concentration of essential metals in organs caused by exposure to cadmium (Cd) and by aging, Cd was administered subcutaneously in single doses of 0.3, 0.9 and 2.7 nig/kg to female rats 10 and 40 weeks of age. The animals were sacrificed on the 7th day after the administration. The concentration of Cd, zinc (Zn), copper (Cu), iron (Fe) and manganese (Mn) in the liver and the kidney was determined and the relations between the concentration of Cd and that of other metals were investigated.1) In 10-week-old rats, the amount of Cd accumulated in the liver and the kidney increased linearly with increasing doses of Cd, while in 40-week-old rats, suppressed accumulation of Cd in the liver and increased accumulation of Cd in the kidney were found after administration of the high dose.2) The concentration of Zn in the liver and the kidney both increased with increasing doses of Cd. There was no age-related difference.3) The concentration of Cu in the liver increased in the animals which received the intermediate and the high dose, irrespective of age. The concentration of Cu in the kidney showed no changes caused by Cd administration or by aging.4) The concentration of Fe in the liver increased in both 10-week-old and 40-week-old rats which received the high dose. The concentration was higher in 40-week-old rats than in 10-week-old rats. The Fe concentration in the kidney and the Mn concentration in the liver and the kidney was not affected by Cd administration or by aging.5) Discriminant analysis, by age, suggested that the amount of metals in the liver and the kidney was more likely to be affected by exposure to Cd in young individuals and less likely to be affected by exposure to Cd with the increase of age.