title: The role of the urothelium and ATP in mediating detrusor smooth muscle contractility.
abstract: OBJECTIVE
  To examine the contractility of urothelium-intact (+UE) and urothelium-denuded (-UE) rat detrusor strips under adenosine triphosphate (ATP) treatment. Purinergic signaling exists in the bladder but both the inhibitory effect of ATP on detrusor contractions and the function of urothelial ATP are not established.
  
  
  METHODS
  Detrusor strips were obtained from bladders of young adult rats. Isometric tension from both transverse and longitudinal contractions was measured using a myograph. The muscarinic agonist carbachol (CCh) was used to induce contractions, which were under the influences of different concentrations of ATP.
  
  
  RESULTS
  In both +UE and -UE strips, 1 mM ATP suppressed CCh-induced contractions. In longitudinal contractions, ATP added to the inhibitory effect of urothelium on CCh responses. Removal of the urothelium, but with exogenous ATP added, recovered the CCh responses to the same level as in +UE strips with no added ATP. Transverse contractions were less susceptible to ATP in the presence of urothelium.
  
  
  CONCLUSIONS
  We showed that the urothelium and ATP suppressed CCh-induced contractions to a similar extent. The findings suggest an inhibitory role of urothelial ATP in mediating detrusor smooth muscle contractility, which may be impaired in diseased bladders.
authors.affiliation: School of Biological Sciences, Nanyang Technological University, Singapore, Singapore.
authors.forename: Aneira Gracia Hidayat
authors.initials: AG
authors.lastname: Santoso
authors.forename: Ika Ariyani Bte
authors.initials: IA
authors.lastname: Sonarno
authors.forename: Noor Aishah Bte
authors.initials: NA
authors.lastname: Arsad
authors.forename: Willmann
authors.initials: W
authors.lastname: Liang
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology / Q000502:physiology*; D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology*; D009130:Muscle, Smooth / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D001743:Urinary Bladder / Q000502:physiology*; D019459:Urothelium / Q000502:physiology*
chemical_list: D000255:Adenosine Triphosphate; D002217:Carbachol