High-level expression of zinc transporter-2 in the rat lateral and dorsal prostate

Zinc is present at high concentrations in the prostate gland, however, the zinc-retention system in the prostate remains obscure. In this study, we investigated the expression of zinc transporters in the rat prostate and found that zinc transporter-2 (ZnT2), which sequesters zinc to the lysosome-like compartment, is expressed at high levels in the lateral prostate (LIP) and dorsal prostate (DIP), and that these areas contain higher levels of zinc than other tissues such as the ventral prostate (VP), liver, and kidney. Zinc levels in LIP from castrated rats were lower than those in sham-operated rats. However, expression of ZnT2 in LIP and DIP was unaffected by castration. Expression of other zinc transporters (ZnT1, ZnT4, and divalent cation transporter 1) did not correlate with zinc levels. These results suggest that factors that regulate zinc homeostasis other than zinc transporters are involved in lowering zinc content after castration in rat prostate.