title: Adrenoceptor function and expression in bladder urothelium and lamina propria.
abstract: OBJECTIVE
  To investigate the role of adrenoceptor subtypes in regulating the spontaneous contractile activity of the inner lining of the urinary bladder (urothelium/lamina propria).
  
  
  METHODS
  The responses of isolated strips of porcine urothelium/lamina propria to noradrenaline, phenylephrine, and isoprenaline were obtained in the absence and presence of receptor subtype-selective antagonists. Quantitative reverse-transcriptase polymerase chain reaction was undertaken to assess the expression of adrenoceptor genes.
  
  
  RESULTS
  The tissues expressed all α1- and β-adrenoceptor subtypes, with the α1A-, α1B-, and β2-adrenoceptors the predominant receptors at the messenger RNA level. In the functional experiments, the rate of phasic contractions and the basal tension were increased by the α1-adrenoceptor agonists phenylephrine (100 μM) and A61603 (10 μM). The rate and tension responses to phenylephrine were reduced by low concentrations of tamsulosin (3 nM) and RS100329 (10 nM) but were unaffected by BMY7378 (100 nM), prazosin (10 nM), and RS17053 (1 μM). In contrast, isoprenaline and salbutamol (both 1 μM) induced a relaxation of tissues and slowing of phasic contractions. The rate and tension responses to isoprenaline were inhibited by propranolol (100 nM) or a combination of CGP20712A (30 nM) and ICI118551 (70 nM). The rate responses were also significantly inhibited by ICI118551 alone (70 nM).
  
  
  CONCLUSIONS
  Although all α1- and β-adrenoceptor subtypes were expressed in the pig urothelium/lamina propria, the α1A/L-adrenoceptor appeared to mediate increases in the contractile rate and tension. The β-adrenoceptor induced inhibition of spontaneous contractile activity appears to be predominately mediated by β2-adrenoceptors, with β1- and β2-adrenoceptors possibly involved in the tension responses.
authors.affiliation: Bond Urology Group, Bond University Faculty of Health Sciences and Medicine, Gold Coast, Queensland, Australia.
authors.forename: Christian
authors.initials: C
authors.lastname: Moro
authors.forename: Lotti
authors.initials: L
authors.lastname: Tajouri
authors.forename: Russ
authors.initials: R
authors.lastname: Chess-Williams
mesh_terms: D058646:Adrenergic alpha-1 Receptor Agonists / Q000494:pharmacology; D058668:Adrenergic alpha-1 Receptor Antagonists / Q000494:pharmacology; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D015870:Gene Expression / Q000187:drug effects*; D066298:In Vitro Techniques; D009092:Mucous Membrane / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D009119:Muscle Contraction / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology; D018340:Receptors, Adrenergic, alpha-1 / Q000235:genetics* / Q000378:metabolism; D011943:Receptors, Adrenergic, beta / Q000235:genetics* / Q000378:metabolism; D013552:Swine; D001743:Urinary Bladder / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D019459:Urothelium / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology
chemical_list: D058646:Adrenergic alpha-1 Receptor Agonists; D058668:Adrenergic alpha-1 Receptor Antagonists; D000316:Adrenergic alpha-Agonists; D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D018340:Receptors, Adrenergic, alpha-1; D011943:Receptors, Adrenergic, beta; D009638:Norepinephrine