MP31-03 DIFFERENCES IN THE CONTRACTILITY OF HUMAN ISOLATED PROSTATIC URETHRA TO OXYTOCIN AND NOREPINEPHRINE IN BENIGN PROSTATIC HYPERPLASIA: POTENTIAL ROLE OF OXYTOCIN IN BPH.

Abstract

You have accessJournal of UrologyBenign Prostatic Hyperplasia: Basic Research1 Apr 2015MP31-03 DIFFERENCES IN THE CONTRACTILITY OF HUMAN ISOLATED PROSTATIC URETHRA TO OXYTOCIN AND NOREPINEPHRINE IN BENIGN PROSTATIC HYPERPLASIA: POTENTIAL ROLE OF OXYTOCIN IN BPH. Stewart McCallum, Celine Rouget, Moez Rekik, Philippe Camparo, Henry Botto, Pascal Rischmann, Philippe Lluel, Stefano Palea, and Timothy Westfall Stewart McCallumStewart McCallum More articles by this author , Celine RougetCeline Rouget More articles by this author , Moez RekikMoez Rekik More articles by this author , Philippe CamparoPhilippe Camparo More articles by this author , Henry BottoHenry Botto More articles by this author , Pascal RischmannPascal Rischmann More articles by this author , Philippe LluelPhilippe Lluel More articles by this author , Stefano PaleaStefano Palea More articles by this author , and Timothy WestfallTimothy Westfall More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.1358AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Previously we have demonstrated that oxytocin (OT) can cause contraction of human prostate through oxytocin receptors. The aim of the present study was to evaluate whether OT can also produce contraction of human isolated prostatic urethra and determine whether this response is mediated by specific OT receptors using the selective oxytocin receptor antagonist epelsiban. METHODS Prostatic urethra was obtained from 8 patients (67 ± 3 years old) undergoing cystoprostatectomy for bladder cancer or prostatic adenomectomy for BPH. Strips were mounted under 1 g of initial tension. After a 60 min equilibration, strips were exposed to 30 μM norepinephrine (NE) to determine tissue viability. After wash-out and 60 min of re-equilibration, epelsiban (30, 100 and 300 nM) or its solvent (distilled water) were incubated for 60 min. Then, a single concentration of oxytocin (1 μM) was tested. In different strips, tamsulosin (10 nM) or its solvent (distilled water) were incubated for 45 min before each addition of NE (0.1-0.3-1-10-30 μM), added in a non cumulative manner RESULTS In preliminary experiments it was determined that cumulative concentration response curves to OT and NE were not possible due to desensitization. In subsequent experiments, the magnitude of contractions induced by 1 μM oxytocin were 11.68 ± 2.68% and 27.21 ± 7.02% (of contractions to 30 μM NE) for strips from cancer and BPH patients respectively (p = 0.0537). Epelsiban inhibited contractions induced by 1 μM OT. However due to the large variability in the response to OT (particularly between the two patient groups), coupled with the low n number (n=5), effects did not reach statistical significance. NE (0.1 – 30 μM) added non-cumulatively, induced concentration-dependent contractions of human isolated prostatic urethra. Interestingly the magnitude of contractions induced by 30 μM NE were different between the two patient groups, however it was the reverse profile in comparison to OT (1.77 ± 0.18 g and 0.99 ± 0.16 g from bladder cancer and BPH patients respectively, p<0.01). Tamsulosin (10 nM) abolished the contractile effect of NE. CONCLUSIONS This is the first demonstration of a contractile effect of OT in human prostatic urethra through specific OT receptors. In addition, OT appears to produce larger responses in tissue from BPH patients. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e356 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Stewart McCallum More articles by this author Celine Rouget More articles by this author Moez Rekik More articles by this author Philippe Camparo More articles by this author Henry Botto More articles by this author Pascal Rischmann More articles by this author Philippe Lluel More articles by this author Stefano Palea More articles by this author Timothy Westfall More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...