216 α1D-ADRENOCEPTOR BLOCKER IMPROVES VOIDING EFFICIENCY BY INCREASE IN SILENT PERIOD OF THE EXTERNAL URETHRAL SPHINCTER IN RATS WITH SPINAL CORD INJURY

Abstract

You have accessJournal of UrologyBladder and Urethra: Anatomy, Physiology and Pharmacology1 Apr 2011216 α1D-ADRENOCEPTOR BLOCKER IMPROVES VOIDING EFFICIENCY BY INCREASE IN SILENT PERIOD OF THE EXTERNAL URETHRAL SPHINCTER IN RATS WITH SPINAL CORD INJURY Hirokazu Ishida, Hiroki Yamauchi, Hironobu Akino, and Osamu Yokoyama Hirokazu IshidaHirokazu Ishida Fukui, Japan More articles by this author , Hiroki YamauchiHiroki Yamauchi Fukui, Japan More articles by this author , Hironobu AkinoHironobu Akino Fukui, Japan More articles by this author , and Osamu YokoyamaOsamu Yokoyama Fukui, Japan More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.326AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES An ideal therapy for lower urinary tract dysfunction in spinal cord injury (SCI) patients would decrease bladder overactivity, thereby, promoting urine storage at low intravesical pressure, and promote efficient voiding at low pressure by decreasing detrusor-sphincter dyssynergia (DSD). In this study we investigated whether α1D-adrenoceptor blocker naftopidil improved voiding dysfunction of chronic SCI rats by monitoring cystometrogram CMG) and external-sphincter electromyogram (EUS-EMG) under unanesthesized state. METHODS The effects of intervenous α1D-adrenoceptor blocker naphtopidil were evaluated during cystometry in decebrated, unanesthetized female Sprague-Dawley rats with spinal cord chronically transected at the T8. Parameters measured included voided volume, residual volume, voiding efficiency, miction pressure, and EUS-EMG which consisted of more prominent tonic activity, shorter periods of bursting activity, and a reduction in the ratio of silent to active periods during bursting in SCI rats. RESULTS Compared to premedication control values, naftopidil ( 0.1, 1, and 3 mg/kg) dose-dependently decreased the number of non-voiding contractions (NVC) per voiding cycle (12.2±7.25 vs. 9±8.56, 6.5±6.74, 2.8±2.71 times, each p<0.05). However, voided volume and maximal pressure of voiding contraction were not significantly affected by naftopidil treatment. Naftopidil (0.1mg/kg, 1mg/kg) decreased residual volume (from 1.96±1.60ml to 1.43±1.60ml, 1.03±1.01ml, respectively; both p<0.05), and increased Voiding efficiency (from 28.5±29.0% to 44±25.8%, 53.4±36.9%, respectively; both p<0.05 ).Compared to control values at EUS-EMG, naftopidil (0.1mg/kg, 1mg/kg, and 3mg/kg) significantly increased burst period (2.46±1.51 sec vs. 8.51±1.45, 11.0±1.05, 9.8±1.50 sec, respectively) and silent period (0.036±0.02 vs. 0.061±0.02, 0.074±0.01, 0.1±0.04 sec). CONCLUSIONS These results suggest that α1D-adrenoceptor blocker reduces NVC and urethral resistance associated with DSD, resulting in improvement voiding efficiency in SCI rats. This report is the first to evaluate the effects of α1D-adrenoceptor blocker on EUS-EMG in SCI models. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e89 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Hirokazu Ishida Fukui, Japan More articles by this author Hiroki Yamauchi Fukui, Japan More articles by this author Hironobu Akino Fukui, Japan More articles by this author Osamu Yokoyama Fukui, Japan More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...