Calcitonin and calcitonin gene-related peptide in the human prostate gland

BACKGROUND. Calcitonin-related peptides have been found in the human prosta te, and calcitonin (CT) and calcitonin gene-related peptide (CGRT) have bee n demonstrated in subpopulations of neuroendocrine (NE) cells. The purpose of this study was to determine the concentrations of CT and CGRP as well as the densities of NE cells in normal prostates, benign prostatic hyperplasi a (BPH), and carcinoma of the prostate (CAP). METHODS. In 42 specimens of radical prostatectomy, the number of CT- and CG RP-immunoreactive NE cells in areas of normal and BPH tissue was determined , and compared with CAP tissue using immunocytochemistry. In addition, by r adioimmunoassay (RIA), tissue levels of CT and CGRP were analyzed in extrac ts from areas of normal, BPH, and CAP tissue, as verified by adjacent histo logic sections; RESULTS. A significant decrease in CT-immunoreactive NE cells was observed in hyperplastic nodules of BPH in comparison to normal tissue. These findin gs were in parallel with a significant reduction in tissue CT level in BPH compared to normal tissue. There was also a marked, but statistically nonsi gnificant, reduction in CT levels in CAP tissue. In contrast, levels of CGR P in BPH and CAP tissue did not show any significant differences compared t o normal tissue. CONCLUSIONS. CT and CGRP are present in NE cells of the human prostate. Cal citonin levels are significantly reduced in BPH, in parallel with a decreas ed number of CT-immunoreactive NE cells, whereas no significant changes in tissue levels of CGRP were observed. The functional significance of these f indings is discussed. (C) 2000 Wiley-Liss, Inc.