Subcellular distribution of zinc in rat prostate studied by x-ray microanalysis: I. Normal prostate.

Zinc is distributed subcellularly throughout the lateral prostate of the rat in both the stromal and epithelial elements. The connective tissue appears to be a major store of zinc. Within the epithelium, the highest concentrations of the element are found in the lysosomes, nucleoli, nuclear chromatin, secretory granules and luminal secretion. Histochemical studies indicate that the metal is bound relatively tightly within the nucleoli (associated with RNA) and in the secretory products of the cytoplasm. Changes in tissue zinc concentration, observed by other workers, following changes in various external stimuli, may not necessarily be reflected by proportionate changes in epithelial concentrations. The role of zinc in the epithelium is considered to be at least two-fold: firstly, for incorporation into vital cellular mechanisms necessary for cell maintenance and, secondly, for involvement in secretory products. It is also possible that the metal participates in the physiology of the sub-epithelial stroma.