Effects of the administration of cadmium and zinc on the concentration of zinc in the thymus of rats.

The zinc content of thymus glands of male Wistar rats has been determined during five weeks of treatment with ZnCl2 and CdCl2, and compared with a group of control rats. Thymus gland extracts were chromatographed on columns of Sephadex G-75 and the zinc content of the one hundred fractions obtained were determined by atomic absorption spectrophotometry. The rats treated with ZnCl2 showed an increase in the thymus concentration of zinc bound to high and low molecular weight proteins. The rats treated with CdCl2 showed an increase in zinc concentration, as opposed to the control group, during the first three weeks of treatment, and thereafter show a toxic effect of cadmium on the gland, with ulterior regression of the latter, and a decrease in the concentration of zinc.