Immunohistochemical distribution of rabbit polyclonal antiurinary protein 1 antibody in the female (Skene's gland) and male prostate: new marker for neuroendocrine cells?

Using rabbit polyclonal antiurinary protein 1 antibody to study the female prostate (Skene's gland) and the male prostate, characteristic localizations patterns appeared in single cells and groups of cells. The majority correspond to cells positive for neuroendocrine markers. In the cytoplasm, cells positive for protein 1 were most frequently found in the epithelial lining of the female urethra, in the pars prostatica of the male urethra, and in the ducts of the female and male prostate where the lining consisted of pseudostratified columnar epithelium. Their occurrence rate was far lower among secretory and basal cells of the male and female prostate glands. The cells with protein 1 corresponded to those displaying positivity for chromogranin A, silver staining by the Grimelius and less by the Sevier-Munger method, and by neuron specific enolase. Using the Masson-Hamperl argentaffin method, positive cells were only exceptionally found. The cells positive for protein 1, and particularly chromogranin A, and characterized by Grimelius positivity, contained different amounts of neuroendocrine granules and varied in size and shape. The majority of these cells had contact with the lumen of male and female prostatic ducts (open type of neuroendocrine cells). In some cases of the male and female urethra and of great paraurethral ducts, a remarkably high number of cells containing protein 1 corresponded to cells only containing neuron-specific enolase but not chromogranin A and other neuroendocrine markers. These cells can be considered stem cells responsible for the renewal of the uroepithelium of the urethra and prostatic ducts. Protein 1 may thus be a further, though presumably not specific marker for the identification of cells of the neuroendocrine system in the prostate of the male and female. This marker could well be used to study uroepithelium maturation. The corresponding immunohistochemical distribution of human protein 1 in neuroendocrine and other cells of the male and the female prostate provides another analogous functional and morphological parameter of prostatic tissue in both sexes and further evidence supporting the non-vestigial concept of the prostate in the female.