The effect of combined exposure to lead and cadmium on the concentration of zinc and copper in rat tissues.

To learn whether a combined exposure to lead and copper provokes disturbances in essential trace elements homeostasis the distribution of zinc and copper in tissues (blood, liver, kidney, heart and brain) after combined and single exposure to lead and/or cadmium was compared. In the same regimen, single or combined exposure accumulation of cadmium and lead in tissues was also measured. Experiments were performed on male Buffalo rats, 5-6 weeks old. Lead acetate (70 mg Pb/kg body wt twice a week) and cadmium chlorate (20 mg Cd/kg body wt once a week) were administered intragastrically for 7 weeks singly or in combination. During the experiment no clinical signs of toxic effect of lead or cadmium were observed. The animals were killed after administration of the last doses of cadmium and/or lead and the level of trace and heavy metals in tissues were measured. The results of this study shows that changes in the copper and zinc concentrations in tissues in the combined exposure to lead and cadmium are similar to those induced by a single lead (heart and brain) or single cadmium (liver and kidney) intoxication. Lead and cadmium concentrations in the liver and kidneys of rats administered with Pb and Cd jointly were significantly lower than those in rats exposed to single doses of Pb or Cd.