1591 ELEVATED POLYAMINE LEVELS IN BLADDER UROTHELIAL CELLS (BUC) FROM SUBJECTS WITH OVERACTIVE BLADDER (OAB) MEDIATE OXOTREMORINE (OXO) EVOKED INTRACELLULAR CALCIUM INCREASE AND ACETYLCHOLINE RELEASE

Abstract

You have accessJournal of UrologyUrodynamics/Incontinence/Female Urology: Incontinence - Evaluation & Therapy II1 Apr 20101591 ELEVATED POLYAMINE LEVELS IN BLADDER UROTHELIAL CELLS (BUC) FROM SUBJECTS WITH OVERACTIVE BLADDER (OAB) MEDIATE OXOTREMORINE (OXO) EVOKED INTRACELLULAR CALCIUM INCREASE AND ACETYLCHOLINE RELEASE Mingkai Li, Yan Sun, Noboru Tomiyia, Yu-chao Hsu, Yuan-chuan Lee, and Toby Chai Mingkai LiMingkai Li More articles by this author , Yan SunYan Sun More articles by this author , Noboru TomiyiaNoboru Tomiyia More articles by this author , Yu-chao HsuYu-chao Hsu More articles by this author , Yuan-chuan LeeYuan-chuan Lee More articles by this author , and Toby ChaiToby Chai More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2010.02.1369AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES To measure intracellular polyamine (putrescine, spermidine, spermine) levels in cultured BUC from OAB and asymptomatic subjects. To assess how polyamines affect OXO evoked intracellular calcium ([Ca2+]i) increase and acetylcholine release in BUC. METHODS BUC were cultured from urothelial biopsies from human OAB and asymptomatic (NB) subjects. High performance liquid chromatography (HPLC) assay with fluorescence detection was used to measure intracellular polyamines level. OAB BUC were treated by 5 mM difluoromethylornithine (DFMO) and 1 mM methylglyoxalbisguanylhydrazone (MGBG) for 72 hours to inhibit the polyamine biosynthesis. OXO (10 μM), a non-specific muscarinic agonist, was used to induce increases in [Ca2+]i levels and release of acetylcholine (ACh). Changes in [Ca2+]i was measured by fura-2 microfluorimetry and ACh was measured by ELISA. RESULTS Putrescine, spermidine and spermine levels, normalized for cell weight (mg tissue), were elevated approximately 2-fold in OAB compared to NB BUC (p<0.01, Fig. 1). Treatment with DFMO and MGBG completely depleted intracellular polyamines. Maximal increase in [Ca2+]i evoked by OXO was significantly greater in OAB compared to in NB BUC (205.10% over baseline ± 18.82 vs 119.54% ± 13.01, p<0.05). After polyamine depletion by DFMO and MGBG, OXO induced [Ca2+]i changes were significantly blunted. OXO induced significantly greater ACh release (p<0.05, Fig. 2) in OAB compared to NB BUC. Similarly, after polyamine depletion, OXO induced ACh release was significantly reduced (p<0.05, Fig. 2). CONCLUSIONS Polyamine levels were significantly elevated in OAB BUC. Activation of muscarinic signaling by OXO evoked greater increase in [Ca2+]i and ACh release in OAB BUC. Depletion of polyamines abrogated these phenotypic changes in OAB BUC. The measurement of intracellular polyamine levels from tissue urothelial biopsies, rather than cultured cells, will be conducted in the near future. Baltimore, MD© 2010 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 183Issue 4SApril 2010Page: e615 Advertisement Copyright & Permissions© 2010 by American Urological Association Education and Research, Inc.MetricsAuthor Information Mingkai Li More articles by this author Yan Sun More articles by this author Noboru Tomiyia More articles by this author Yu-chao Hsu More articles by this author Yuan-chuan Lee More articles by this author Toby Chai More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...