Hepatic and renal metallothionein concentrations in cows, swine, and chickens given cadmium and lead in feed.

Dairy cows, growing swine, and laying chickens were given supplemental cadmium (Cd) at concentrations of approximately 2 and 10 ppm in feed as cadmium chloride and were given lead at concentrations of 5 and 25 ppm in feed as lead acetate for 12 to 24 weeks. Metallothionein (MT) and Cd concentrations increased more in renal than in hepatic tissues of the Cd-treated animals. The hepatic MT values in pigs and chickens and the renal MT values in all species continued to increase for several weeks after Cd feeding was stopped. A significant correlation between Cd and MT concentrations of the hepatic and the renal tissues was observed, except in bovine liver. The feeding of lead did not have any effect on the hepatic or the renal MT concentrations in cows, pigs, and chickens. Dietary Cd and possibly some other metals, but not lead, may be determinants of concentration of metal binding protein in tissues.