title: 5-HT2Areceptor enhancement of contractile activity of the porcine urothelium and lamina propria.
abstract: To examine the effect of 5-hydroxytryptamine (5-HT; serotonin) on the contractile properties of the urothelium and lamina propria, as a better understanding of bladder physiology might aid the development of new treatments.
  
  
  
  Strips of porcine urothelium and lamina propria were suspended in gassed Krebs-bicarbonate solution, and cumulative concentration-response curves for 5-HT were generated in the absence and presence of 5-HT antagonists, Nω-nitro-l-arginine and indomethacin. Responses to α-methyl-5-HT were also examined.
  
  
  
  Strips of urothelium/lamina propria developed spontaneous contractions, whereas the addition of 5-HT induced concentration-dependent increases in contractile tone with maximal contractions of 50.43 ± 2.78 mN/g tissue weight (n = 100). Tonic contractions to 5-HT were unchanged in the presence of Nω-nitro-l-arginine (100 μmol/L) or indomethacin (5 μmol/L). Selective concentrations of the antagonists methiothepin (5-HT1&2, 100 nmol/L), RS102221 (5-HT2C, 30 nmol/L), ondansetron (5-HT3, 30 nmol/L), GR113808, (5-HT4, 100 nmol/L), SB699551 (5-HT5, 10 nmol/L), SB399885 (5-HT6, 100 nmol/L) and SB269970 (5-HT7, 10 nmol/L) did not influence responses to 5-HT. However, the 5-HT2Aantagonist, ketanserin (30-300 μmol/L), caused a shift of the 5-HT curve yielding an affinity estimate of 7.9.
  
  
  
  The results show that contractile responses of the urothelium/lamina propria to 5-HT are predominantly mediated through the 5-HT2Areceptor.
authors.affiliation: Centre for Urology Research, Faculty of Health Sciences and Medicine, Bond University, Gold Coast, Queensland, Australia. cmoro@bond.edu.au.
authors.forename: Christian
authors.initials: C
authors.lastname: Moro
authors.affiliation: Centre for Urology Research, Faculty of Health Sciences and Medicine, Bond University, Gold Coast, Queensland, Australia.
authors.forename: Lily
authors.initials: L
authors.lastname: Edwards
authors.affiliation: Centre for Urology Research, Faculty of Health Sciences and Medicine, Bond University, Gold Coast, Queensland, Australia.
authors.forename: Russ
authors.initials: R
authors.lastname: Chess-Williams
mesh_terms: D000818:Animals; D009092:Mucous Membrane; D009119:Muscle Contraction; D044402:Receptor, Serotonin, 5-HT2A / Q000502:physiology*; D012702:Serotonin Antagonists; D013552:Swine; D019459:Urothelium / Q000502:physiology*
chemical_list: D044402:Receptor, Serotonin, 5-HT2A; D012702:Serotonin Antagonists
keywords: 5-hydroxytryptamine; bladder; lamina propria; serotonin; urothelium