The effect of low doses of dietary cadmium oxide on the disposition of trace elements (zinc, copper, iron), hematological parameters, and liver function in rats

Abstract

The Zn, Cu, and Fe concentrations in selected organs, tissues and in the excreta of male Wistar rats, exposed to dietary CdO (2.80 and 7.15 ppm) for 40 and 60 days, were investigated. Concomitantly hematological values and serum enzyme activities were recorded. Zn levels of spleen, kidney, testes, muscle and feces were not affected by the Cd treatment. After 40 days of Cd exposure, the Zn concentration in the hair decreased, while the Zn level of the lung slightly increased. During the feeding trial, Cd produced an increase of liver Zn by about 24%. Femur Zn decreased and Zn in urine increased after 60 days of exposure to 7.15 ppm Cd. Except in hair and urine, the Cu concentration in all organs and tissues investigated remained unchanged. Hair Cu levels decreased after 40 days of Cd exposure but increased after 60 days. At this time, elevated Cu concentration in urine was recorded. After exposure to 7.15 ppm Cd, the Fe content of the lung, liver, spleen, testes, muscle, femur and blood decreased significantly. After 60 days on the 7.15 ppm diet, highest reductions (30%–60%) of Fe content were recorded in the lung, liver, and spleen. Similar to Zn and Cu, the Fe concentration in urine increased at that time. No changes were found in the Fe content of hair, kidney, and feces. In spite of a disturbed Fe metabolism, an anaemic response of Cd-treated rats was not observed. Hematocrit and hemoglobin remained unchanged and the number of red blood cells slightly increased after 40 days of Cd exposure. While the activity of serum alkaline phosphatase was not affected by dietary Cd, the activities of serum-GOT and serum-GPT increased after exposure to 7.15 ppm Cd indicating disturbed hepatic functions.