Abstract: 508

SEROTONINERGIC NEUROENDOCRINE CELLS AND NEUROPEPTIDE Y INNERVATION IN HUMAN BENIGN PROSTATE HYPERPLASIA. IMMUNOHISTOCHEMICAL AND QUANTITATIVE STUDY.

Luis Santamaria^{1 *}, Rocio Martin² , Jose Juan Martin³ , Lucia Alonso¹
Department of Morphology, School of Medicine, UAM, Madrid, Spain ¹
Department of Pathology, Clinica La Zarzuela, Madrid, Spain ²
Department of Anaesthesiology, Hospital Ramon y Cajal, Madrid, Spain ³

This study was addressed to ascertain if the peptidergic innervation and the neuroendocrine cells (NEC), play a role in human benign prostate hyperplasia (BPH). The study was performed in the transition zone (TZ) of 8 normal prostates, and in specimens from 50 patients diagnosed of BPH. Immunohistochemical methods were used for detection of chromogranin (CG), serotonin (SER), and protein gene product 9.5 (PGP 9.5) in NEC, and for visualization of PGP 9.5, neuropeptide Y (NPY), and vasoactive intestinal polypeptide (VIP), in nerve fibres from TZ and BPH. The amount of NEC was estimated using the optical disector, and expressed as numerical density (Nv=number of cells/mm³ of tissue), and as absolute number (Nc=Nv×prostate volume). The nerve fibre immunoreactivity was evaluated estimating the volume fraction (VF) of immunostaining (ie: immunoreactive area/reference area), and the absolute volume of immunostaining (VI=VF×prostate volume). The means±SD were compared by ANOVA between TZ and BPH cases. A logistic regression model was used to test the ability to predict the BPH status using Nc (CG, SER, PGP 9.5 cells), and VI (PGP 9.5, NPY, and VIP fibres) as independent variables. Comparing Nv between TZ and BPH, there was a significant increase in TZ (p<0.01) for all the types of NEC, whereas the Nc for SER was significantly increased (p<0.01) in BPH. The VF for PGP and NPY nerves was significantly (p<0.01) higher in TZ than in BPH. There was not significant changes in VI for the other immunoreactive nerves. Nc for SER was a positive predictive variable, and VI for NPY was a negative one in the logistic model for the chance to develop BPH. The other variables have not predictive significance. In conclusion, (1), the results for the serotoninergic NEC agree with a role of the serotonin in the cell proliferation in prostate, and (2), NPY innervation decreases as the hyperplastic growth increases.

    This abstract is being presented on Tuesday, August 3 at 8:00 AM to 10:15 AM at CUB 2nd Floor Ballroom.