MP12-03 FUNCTIONAL CHANGES OF THE BLADDER IN VIVO IN MICE LACKING TRANSIENT RECEPTOR POTENTIAL MELASTAIN 2 (TRPM2) CHANNELS

Abstract

You have accessJournal of UrologyUrodynamics/Incontinence/Female Urology: Basic Research II1 Apr 2015MP12-03 FUNCTIONAL CHANGES OF THE BLADDER IN VIVO IN MICE LACKING TRANSIENT RECEPTOR POTENTIAL MELASTAIN 2 (TRPM2) CHANNELS Jun Kamei, Naoki Aizawa, Takayuki Nakagawa, Hiroki Ito, Rino Sugiyama, Yoshiyuki Akiyama, Koji Ichihara, Shuji Kaneko, Yukio Homma, and Yasuhiko Igawa Jun KameiJun Kamei More articles by this author , Naoki AizawaNaoki Aizawa More articles by this author , Takayuki NakagawaTakayuki Nakagawa More articles by this author , Hiroki ItoHiroki Ito More articles by this author , Rino SugiyamaRino Sugiyama More articles by this author , Yoshiyuki AkiyamaYoshiyuki Akiyama More articles by this author , Koji IchiharaKoji Ichihara More articles by this author , Shuji KanekoShuji Kaneko More articles by this author , Yukio HommaYukio Homma More articles by this author , and Yasuhiko IgawaYasuhiko Igawa More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2015.02.778AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES We have previously reported that there were no remarkable differences in the in vitro contractile responses of isolated detrusor smooth muscle strips to either high K+, carbachol, or electrical field stimulation between TRPM2 knock-out (KO) and wild type (WT) mice in either sexes. In this study, to further disclose the role of TPM2 channels on lower urinary tract function, we evaluated in vivo bladder function of TRPM2-KO mice by using frequency-volume (FV) measurement, and cystometry (CMG) measurements under a conscious, free-moving as well as a decerebrated, unanesthetized condition. METHODS Male and female TRPM2-KO and WT mice (10–12 weeks-old) were used. In the FV measurements, voiding behavior was monitored for 24 hours by placing the mouse in a metabolic cage that enables to measure voided urine volumes precisely. Conscious CMG measurements were performed with continuous saline-instillation (15 μl/min) in a free-moving condition at 5 days after implantation of a bladder catheter through the dome. In the CMG measurements in a decerebrated condition, mice underwent cystostomy formation and supracollicular decerebration under isoflurane-anesthesia. After recovery from the anesthesia (waiting for at least 2 hours), CMG was carried out with saline-instillation at 10 μl/min. RESULTS In the FV measurements, in females, mean voided volume and mean flow rate in TRPM2-KO mice were significantly greater than those in WT mice. In males, similar tendencies were observed, but there were no significant differences (n = 10, in each group). In the conscious CMG measurements, in females, threshold pressure, micturition pressure, intercontraction interval and mean voided volume in TRPM2-KO mice were significantly greater than those in WT mice. In contrast, in male mice, only threshold pressure in TRPM2-KO mice was significantly higher than that in WT mice (Figure 1A, n = 8 in each group). In the CMG measurements in the decerebrated condition, only threshold pressure in TRPM2-KO mice was significantly higher than that in WT mice in both sexes (Figure 1B, male TRPM2-KO n = 7, other groups n = 8). CONCLUSIONS The present study suggests that TRPM2 channels may have a role in modulating bladder mechano-sensation in mice, and also that this contribution might be more remarkable in females. © 2015 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 193Issue 4SApril 2015Page: e128-e129 Advertisement Copyright & Permissions© 2015 by American Urological Association Education and Research, Inc.MetricsAuthor Information Jun Kamei More articles by this author Naoki Aizawa More articles by this author Takayuki Nakagawa More articles by this author Hiroki Ito More articles by this author Rino Sugiyama More articles by this author Yoshiyuki Akiyama More articles by this author Koji Ichihara More articles by this author Shuji Kaneko More articles by this author Yukio Homma More articles by this author Yasuhiko Igawa More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...