title: Effect of naftopidil, an alpha1D/A-adrenoceptor antagonist, on the urinary bladder in rats with spinal cord injury.
abstract: OBJECTIVE
  Alpha1D-adrenoceptors (α1D-ARs) located in the spinal cord are involved in the control of lower urinary tract function. In order to clarify the effect of α1D-ARs on storage function in the spinal cord, we examined the effect of oral administration and intrathecal injection of the α1D/A-AR antagonist, naftopidil, on bladder activity, as well as the effect of naftopidil on bladder wall histology, in female rats with spinal cord injury (SCI).
  
  
  METHODS
  Adult female Sprague-Dawley rats with Th9-10 spinal cord transection were used. In SCI rats with or without 5mg/day of naftopidil for 4weeks, bladder activity was examined via continuous cystometry. In other SCI rats, bladder activity was examined before and after intrathecal injection of naftopidil. In addition, bladder wall histology was compared between SCI rats with or without oral administration of naftopidil for 4weeks.
  
  
  RESULTS
  Oral administration of naftopidil decreased the number of non-voiding contractions (NVCs). Intrathecal injection of naftopidil prolonged the interval between voiding contractions, decreased the maximum voiding contraction pressure and the number of NVCs, and increased bladder capacity without affecting the residual urine volume. Oral administration of naftopidil also decreased bladder wall fibrosis.
  
  
  CONCLUSIONS
  The α1D/A-AR antagonist naftopidil might act on the bladder and spinal cord to improve detrusor hyperreflexia in the storage state in SCI female rats. Naftopidil also suppressed bladder wall fibrosis, suggesting that it may be effective for the treatment of neurogenic lower urinary tract dysfunction after SCI.
authors.affiliation: Southern Knights' Laboratory LLP, Okinawa, Japan; Department of Urology, Okinawa Kyodo Hospital, Okinawa, Japan. kadekawa_k@yahoo.co.jp
authors.forename: Katsumi
authors.initials: K
authors.lastname: Kadekawa
authors.forename: Kimio
authors.initials: K
authors.lastname: Sugaya
authors.forename: Saori
authors.initials: S
authors.lastname: Nishijima
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Ashitomi
authors.forename: Minoru
authors.initials: M
authors.lastname: Miyazato
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Ueda
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Yamamoto
mesh_terms: D000284:Administration, Oral; D000317:Adrenergic alpha-Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D005260:Female; D009281:Naphthalenes / Q000008:administration & dosage / Q000494:pharmacology*; D010879:Piperazines / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D018340:Receptors, Adrenergic, alpha-1 / Q000187:drug effects*; D013119:Spinal Cord Injuries / Q000503:physiopathology*; D001743:Urinary Bladder / Q000187:drug effects* / Q000503:physiopathology
chemical_list: D000317:Adrenergic alpha-Antagonists; D009281:Naphthalenes; D010879:Piperazines; D018340:Receptors, Adrenergic, alpha-1; C064357:naftopidil