Metallothionein levels in liver and kidney of Canadians--a potential indicator of environmental exposure to cadmium.

Liver and kidney cortex samples were obtained from 89 human autopsies for the determination of metallothionein (MT), cadmium (Cd), zinc (Zn), and copper (Cu). An age-dependent increase of Cd, Zn, and Cd/Zn was observed in the kidney; increases peaked at mid-age and were followed by a decline. Cadmium was present at a low constant level in the liver at all ages. The mean concentrations of Cd and Zn were 18.0 and 40.1 micrograms/g wet weight, respectively, in the kidney, and for the liver the values for Cd and Zn were 2.0 and 79.0 micrograms/g wet weight, respectively. A positive linear relationship was observed between Cd or Zn and MT in the kidney and between Zn and MT in the liver. No other correlation was found between Cu and MT in either organs. Similar values were obtained for MT when estimated by Ag-hem and Cd-hem methods.