PD24-09 POST-INJURY TIME COURSE OF LOWER URINARY TRACT DYSFUNCTION AFTER SPINAL CORD INJURY (SCI) IN THE MOUSE MODEL

Abstract

You have accessJournal of UrologyBladder & Urethra: Anatomy, Physiology & Pharmacology II (PD24)1 Apr 2020PD24-09 POST-INJURY TIME COURSE OF LOWER URINARY TRACT DYSFUNCTION AFTER SPINAL CORD INJURY (SCI) IN THE MOUSE MODEL Tetsuichi Saito*, Masahiro Kurobe, Daisuke Gotoh, Taro Igarashi, Osamu Ishizuka, and Naoki Yoshimura Tetsuichi Saito*Tetsuichi Saito* More articles by this author , Masahiro KurobeMasahiro Kurobe More articles by this author , Daisuke GotohDaisuke Gotoh More articles by this author , Taro IgarashiTaro Igarashi More articles by this author , Osamu IshizukaOsamu Ishizuka More articles by this author , and Naoki YoshimuraNaoki Yoshimura More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000881.09AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Lower urinary tract dysfunction (LUTD) due to SCI causes detrusor overactivity (DO) and detrusor sphincter dyssynergia (DSD) leading to inefficient voiding with increased residual urine. Animal models of SCI have been used to study these conditions; however, the adequate timing of evaluation after SCI in mouse models has not been explored. Thus, this study evaluated the time-course changes of bladder and external urinary sphincter (EUS) activity as well as mechanosensitive channels in L6-S1 dorsal root ganglia (DRG). METHODS: Female C57BL/6N mice were used and SCI was induced by Th8/9 spinal cord transection. The mice were divided into 3 groups; A: 2 weeks post SCI, B: 4weeks post SCI and C: 6 weeks post SCI, and evaluated by single-filling cystometery and EUS-electromyography (EMG) under an awake condition. After evaluation, L6-S1 DRG were harvested to measure mRNA expression of TRP channels and mechanosensitive ion channels such as ASICs and Piezo. RESULTS: In SCI mice, non-voiding contractions (NVC) during bladder filling were confirmed at 2 weeks post-SCI and did not increase over time to 6 weeks (Fig. 1A). In EUS-EMG measurements, DSD was observed at 2 weeks, but periodic EMG reductions during bladder contraction, resulting in urination, were not observed in most 2-weeks SCI mice, thereby leading to urinary retention (Fig. 1A). At 4 weeks, SCI mice showed increases of EMG activity reduction time with increased voiding efficiency (VE). At 6 weeks, SCI mice exhibited further increases in bladder capacity, residual volume and EMG reduction time compared to groups A and B without significant changes in VE compared to 4 weeks (Fig. 1A). RT-PCR of L6-S1 DRG showed increased mRNA levels of TRPV1 and ASIC1-3 in SCI mice with a decrease of ASIC2-3 at 6 weeks compared to 4 weeks while Piezo2 showed a slow increase at 6 weeks (Fig. 1B). CONCLUSIONS: These results indicate that DO evident as NVC is established in the early phase (2weeks) whereas DSD is completed later at 4weeks with a slight improvement evident as increased EMG reduction time at 6 weeks post SCI, and that ASIC and Piezo2 mechanosensitive channels may be involved in the establishment of DSD in early (2-4 weeks) and late phases (4-6 weeks) of SCI, respectively. These data would help us to understand the progression mechanisms of SCI-induced LUTD. Source of Funding: DOD W81XWH-17-1-0403 © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e535-e536 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information Tetsuichi Saito* More articles by this author Masahiro Kurobe More articles by this author Daisuke Gotoh More articles by this author Taro Igarashi More articles by this author Osamu Ishizuka More articles by this author Naoki Yoshimura More articles by this author Expand All Advertisement PDF downloadLoading ...