Comparison of cadmium-metallothionein synthesis in parenchymal and non-parenchymal rat liver cells.

The time course of cadmium-metallothionein synthesis was studied in non-parenchymal and parenchymal cells, isolated by a cell-separation technique from the livers of rats after the simultaneous injection of CdCl2 (0.05 mg of Cd/kg) and a 10-fold molar excess of 2,3-dimercaptopropanol. Under these conditions of dosing, in contrast with the injection of CdCl2 alone, both cell types accumulate similar concentrations of Cd and synthesize equivalent concentrations of metallothionein. It is concluded that both cell types have a similar capacity to synthesize the metalloprotein, and that the limiting factor under normal cadmium exposure is the relatively inefficient metal uptake into the non-parenchymal cells.