Nuclear zinc in the three lobes of the rat prostate gland.

The prostate gland concentrates Zn more than any organ in the body and Zn is increased and decreased in benign prostatic hyperplastic and adenocarcinoma of the prostate, respectively. Zn is a key structure in zinc finger proteins and hence is involved in cell proliferation and differentiation. The role of Zn may be attributed to a zinc binding protein, metallothionein (MT), which can be induced by certain metals, e.g. Cd. Induced MT may be involved in Zn metabolism and transport in the prostate gland. X-ray microanalysis was used to detect quantitatively the Zn in the nuclei of the glandular epithelium of the gland. It was found that Zn concentration was elevated and reduced in the lateral and dorsal lobes, respectively, after Zn treatment, but the Zn concentration was elevated in the lateral lobe after cadmium treatment. The ventral lobe did not show any substantial change in Zn concentration after either treatment. These results suggest that the three lobes of the gland respond differently to treatment. The variations in the response may reflect different mechanisms of Zn transport and metabolism in the three lobes of the rat prostate. Binding Zn to MT may indicate the involvement of MT in the metabolism and transport of zinc, an effect which may be modified by treatment.