Neuroendocrine cells and nerves in the prostate of the guinea pig: Effectsof peripheral denervation and castration

BACKGROUND. Neuroendocrine (NE) cells and nerves in the prostate gland are thought to play a central role in the regulation of growth, cellular differ entiation and homeostasis of secretory activity. The objective of this expe rimental study was to describe the effects of peripheral denervation and ca stration on NE cells and nerves in the guinea pig prostate. METHODS. Guinea pigs underwent sham-operation, unilateral and bilateral hyp ogastric nerve resection, extirpation of the right anterior major pelvic ga nglion (AMPG), autotransplantation of prostatic tissue and castration. Cryo stat sections of prostatic tissue were examined with immunohistochemistry b y using serotonin (5-HT) and chromogranin A (CgA) and various neuropeptides . RESULTS. The number of 5-HT-IR NE cells was four-fold higher than CgA-IR NE cells. The innervation pattern was uniform throughout the gland with subep ithelial nerves in close proximity to NE cells. Autotransplants of prostati c tissue showed total loss of nerves, but the number and morphology of 5-HT -IR NE cells were unaltered. Extirpation of the right AMPG showed significa nt reduction in prostate weight, decreased density of nerve terminals in th e superior part of the ipsilateral prostate, whereas the number and morphol ogical feature of 5-HT-IR NE cells remained unaffected in the entire prosta te. Castration induced atrophy of the gland with a significant reduction in weight (unpaired t-test, P < 0.001), but without effect upon 5-HT-IR NE ce lls. CONCLUSIONS. The guinea pig seems to be a useful animal model for studies o n the role of the NE cells in the prostate, NE cells seem to be independent of innervation and androgens. It seems that other factors influence the NE cell population to a greater extent. (C) 2001 Wiley-Liss,Inc.