title: Sensory neurone-specific receptor-mediated regulation of micturition reflex in urethane-anaesthetized rats.
abstract: OBJECTIVE
  •  To investigate the effect of sensory neurone-specific receptors (SNSRs) activation on the micturition reflex in rats.
  
  
  METHODS
  •  Continuous cystometrograms (CMGs, 0.04 mL/min) were performed in female Sprague-Dawley rats under urethane anaesthesia. •  After stable micturition cycles were established, a selective rat SNSR1 agonist, bovine adrenal medulla 8-22 (BAM8-22), was administered intravenously (i.v.) or intrathecally (i.t.) in normal rats or rats pretreated with capsaicin 4 days before the experiments. •  Micturition variables were recorded and compared before and after drug administration.
  
  
  RESULTS
  •  Administration (i.v.) of BAM8-22 (3-100 µg/kg) significantly increased intercontraction intervals in a dose-dependent fashion, but did not affect residual urine or baseline pressure at any doses tested. •  Administration (i.t.) of BAM8-22 (0.01-0.3 µg) also increased intercontraction intervals in a dose-dependent fashion, but did not affect residual urine or baseline pressure at any doses tested. •  These inhibitory effects of i.v. (30 µg/kg) or i.t. (0.3 µg) administration of BAM8-22 still occurred after capsaicin pretreatment.
  
  
  CONCLUSIONS
  •  These results indicate that in urethane-anaesthetized rats activation of SNSRs can inhibit the micturition reflex via pathways independent of capsaicin-sensitive C-fibres. •  Thus SNSRs could be a potential target for the treatment of bladder dysfunction, e.g. overactive bladder.
authors: Department of Urology, Tottori University School of Medicine, Yonago, Japan.
authors: Masashi
authors: M
authors: Honda
authors: Atsushi
authors: A
authors: Takenaka
authors: Seiya
authors: S
authors: Inoue
authors: Michael B
authors: MB
authors: Chancellor
authors: Naoki
authors: N
authors: Yoshimura
mesh_terms: D000283:Administration, Intravesical; D000344:Afferent Pathways / Q000187:drug effects; D000818:Animals; D005260:Female; D010446:Peptide Fragments / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D043562:Receptors, G-Protein-Coupled / Q000037:antagonists & inhibitors*; D012018:Reflex / Q000502:physiology*; D011984:Sensory Receptor Cells / Q000502:physiology*; D001743:Urinary Bladder / Q000294:innervation; D014554:Urination / Q000502:physiology*
chemical_list: D010446:Peptide Fragments; D043562:Receptors, G-Protein-Coupled; C571042:bovine adrenal medulla 8-22; C000591603:Mrgprc protein, rat