You have accessJournal of UrologyUrodynamics/Incontinence/Female Urology: Urodynamic Testing1 Apr 20101619 EFFECTS OF INTRATHECAL INJECTION OF ALPHA-1A AND -1D ADRENOCEPTOR BLOCKERS ON BLADDER ACTIVITY IN SPINAL CORD INJURED RATS Katsumi Kadekawa, Minoru Miyazato, Saori Nishijima, Katsuhiro Ashitomi, and Kimio Sugaya Katsumi KadekawaKatsumi Kadekawa Okinawa, Japan More articles by this author , Minoru MiyazatoMinoru Miyazato Sendai, Japan More articles by this author , Saori NishijimaSaori Nishijima Okinawa, Japan More articles by this author , Katsuhiro AshitomiKatsuhiro Ashitomi Okinawa, Japan More articles by this author , and Kimio SugayaKimio Sugaya Okinawa, Japan More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2010.02.1399AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Alpha1-adrenoceptor (α1-AR) blockers are used as the medications of first choice for the treatment of benign prostatic hyperplasia (BPH). Since α1-AR blockers relax the smooth muscle in the prostate and decrease the resistance to urine flow in the prostatic urethra, these agents have been used for the treatment of voiding disorders in BPH patients. Their administration not only improves voiding symptoms, but also reduces bladder collecting symptoms such as urinary frequency or nocturia. However, the mechanism involved in the improvement of collecting disorders by α1-AR blockers has not yet been clarified. Therefore, in the present study, in order to investigate whether α1-AR blockers act in the spinal cord to improve collecting disorders, the effects of intrathecal injection of α1A- and α1D-AR blockers (silodosin and naftopidil, respectively) on bladder function were examined in the spinal cord injured (SCI) rats. METHODS Adult female Sprague-Dawley rats were used 4 weeks after Th9-10 spinal cord transection. Continuous cystometry via the cystostomy was performed under an awake condition, and bladder activities were measured before and after intrathecal silodosin (0.01-100 μg, n=7) and naftopidil (0.01-100 μg, n=7) at the level of L6-S1 spinal cord in SCI rats. RESULTS Intrathecal injection of higher dose (100 μg) of silodosin decreased the maximal bladder contraction pressure and the number of low amplitude rhythmic intravesical pressure waves (pressures > 8 cm H2O) without release of fluid from the urethra (nonvoiding contractions; NVCs). Intrathecal injection of naftopidil (0.1-100 μg) decreased the maximal bladder contraction pressure and the number of NVCs, and prolonged the interval between bladder contractions. Voiding efficacy was also improved after intrathecal injection of both agents. CONCLUSIONS α1-AR blockers (especially α1D-AR) applied in the lumbosacral spinal cord improved urine storage function, possibly via inhibition of C-fiber bladder afferent pathway. α1A- and α1D-AR are widely distributed in the central nervous system, including the spinal cord. Therefore, if α1-AR blockers pass the blood-brain barrier, they could act in the spinal cord to improve storage function in patients with detrusor overactivity. © 2010 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 183Issue 4SApril 2010Page: e625 Advertisement Copyright & Permissions© 2010 by American Urological Association Education and Research, Inc.MetricsAuthor Information Katsumi Kadekawa Okinawa, Japan More articles by this author Minoru Miyazato Sendai, Japan More articles by this author Saori Nishijima Okinawa, Japan More articles by this author Katsuhiro Ashitomi Okinawa, Japan More articles by this author Kimio Sugaya Okinawa, Japan More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...