Metallothionein, cadmium, copper and zinc levels of human and rat tissues.

Metallothionein (MT), zinc (Zn), copper (Cu) and cadmium (Cd) were determined in 10 tissues (brain, heart, kidney cortex, liver, lung, muscle, pancreas, small intestine, spleen and stomach) from human autopsies (10 male individuals, mean age 43 +/- 9 years, all smokers) and Wistar rats. The mean tissue concentrations of MT in the human samples varied between 3.8 and 495 micrograms/g wet weight in spleen and kidney cortex, respectively. In most tissues human MT levels were high as compared to rats; particularly in liver and kidney cortex human MT levels exceeded those of rats about 25- and 10-fold, respectively. Positive linear relationships were observed between Zn or Cu and MT in human liver and between Cd and MT in human kidney cortex.