title: Relaxant effects of beta-adrenergic agonists on porcine and human detrusor muscle.
abstract: OBJECTIVE
  Relaxant effects of different beta-adrenoceptor agonists on porcine and human detrusor were examined. Thus, the beta-adrenoceptor subtype mainly responsible for relaxation in the detrusor muscle of pigs was characterized. Additionally, different effects of several beta-agonists in both species were shown.
  
  
  METHODS
  Experiments were performed on muscle strips of porcine and human detrusor suspended in a tissue bath. The relaxant effects of the non-selective beta-agonist isoprenaline, the selective beta2-agonists procaterol, salbutamol and the selective beta3-agonists BRL 37344, CL 316 243 and CGP 12177 on potassium-induced contraction were investigated. The inhibitory effect of different substances on the maximum contraction and the rank order of potency for endogenous catecholamines was determined in pigs. Furthermore, concentration-relaxation curves were performed for pigs and humans.
  
  
  RESULTS
  Pigs: In the pre-treatment experiments isoprenaline and procaterol showed similar effects. The concentration-response experiments showed that the maximum relaxation induced by procaterol and salbutamol was more than 90%, not significantly different from isoprenaline, whereas the maximum relaxations of CL 316 243, BRL 37344 and CGP 12177 amounted to 68, 70 or 30%, respectively. Rank order of potencies was isoprenaline > or = adrenaline > noradrenaline. Humans: Isoprenaline, procaterol, salbutamol and CL 316 243 showed a maximum relaxation of 80, 41, 24 and 35% and pD2 values of 6.24, 5.65, 5.48 and 5.55, respectively.
  
  
  CONCLUSIONS
  Beta2-receptors play a main functional role in mediating relaxation of porcine detrusor. Selective beta2- and beta3-agonists similarly relax the human detrusor. Effects were smaller compared with the pig.
authors.affiliation: Department of Urology, University Hospital Mannheim, Theodor-Kutzer-Ufer 1-3, Mannheim, Germany. jasmin-katrin.badawi@uro.ma.uni0heidelberg.de
authors.forename: J K
authors.initials: JK
authors.lastname: Badawi
authors.forename: H
authors.initials: H
authors.lastname: Uecelehan
authors.forename: M
authors.initials: M
authors.lastname: Hatzinger
authors.forename: M S
authors.initials: MS
authors.lastname: Michel
authors.forename: A
authors.initials: A
authors.lastname: Haferkamp
authors.forename: S
authors.initials: S
authors.lastname: Bross
mesh_terms: D000318:Adrenergic beta-Agonists / Q000378:metabolism* / Q000494:pharmacology*; D000368:Aged; D000420:Albuterol / Q000494:pharmacology; D000818:Animals; D004149:Dioxoles / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004837:Epinephrine / Q000494:pharmacology; D004983:Ethanolamines / Q000494:pharmacology; D005260:Female; D006801:Humans; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D009638:Norepinephrine / Q000494:pharmacology; D017265:Procaterol / Q000494:pharmacology; D011412:Propanolamines / Q000494:pharmacology; D013552:Swine
chemical_list: D000318:Adrenergic beta-Agonists; D004149:Dioxoles; D004983:Ethanolamines; D011412:Propanolamines; C076126:disodium (R,R)-5-(2-((2-(3-chlorophenyl)-2-hydroxyethyl)-amino)propyl)-1,3-benzodioxole-2,3-dicarboxylate; C057368:BRL 37344; D007545:Isoproterenol; D000420:Albuterol; C033394:CGP 12177; D009638:Norepinephrine; D017265:Procaterol; D004837:Epinephrine