NEUROHORMONAL STIMULATION OF HISTAMINE-RELEASE FROM NEUROENDOCRINE CELLS OF THE HUMAN ADENOMATOUS PROSTATE

BACKGROUND. Neuroendocrine cells (NE) constitute a population of highl y specialized cells in prostatic glands; histamine has never been desc ribed in these cells. This article shows the presence and the regulati on of release of histamine in NE. METHODS. In 21 prostatic adenomas, N E were identified by specific antisera against neuroendocrine markers (chromogranin-A, synaptophysin), histamine, and histidine decarboxylas e (HDC); a rat HDC-cDNA probe was used to detect this enzyme by in sit u hybridization. RESULTS. Immunoreactive cells for chromogranin-A, his tamine, and HDC were found among luminal epithelial glandular cells. S imilar cells were also labeled with the HDC-cDNA probe. Glandular cell s, isolated from prostatic adenomas, were shown to contain histamine ( 7-40 pmol/mg cellular protein). L(-) norepinephrine causes a time-depe ndent (t(1/2) = 22 min) histamine release; the alpha(1)-receptor antag onists WB-4101 and YM-617 specifically inhibited this release, in agre ement with a mediation by alpha(1)-adenoreceptor subtype. CONCLUSIONS. There is some evidence for the presence in prostatic adenomas of hist amine-forming cells of neuroendocrine type; histamine release from the se cells is under the control of alpha(1)-adrenoreceptor subtype. (C) 1998 Wiley-Liss, Inc.