title: Evidence for the presence of beta-3-adrenoceptors mediating relaxation in the human oviduct.
abstract: Beta1- and beta2-adrenoceptors mediate relaxation in the oviductal smooth muscle. This study examines the existence and function of beta3-adrenoceptors in the human oviduct. Ring segments of the oviduct were set up for isometric tension recording. The effect of isoprenaline and BRL 37344 on smooth muscle tone was examined. The expression of beta3-adrenoceptors in the oviduct was also examined. Isoprenaline and BRL 37344 concentration-dependently relaxed circular muscles of the oviduct. BRL 37344 was less potent than isoprenaline and was a partial agonist. Propranolol shifted isoprenaline but not BRL 37344 concentration-response curve to the right without reducing the maximum response. Cyanopindolol (1 micromol/l), a beta3-adrenoceptor antagonist, shifted the isoprenaline concentration response curve to the right. The -log K(B) value of 7.8 indicates activation of beta3-adrenoceptors by isoprenaline. mRNA for beta3-adrenoceptors was expressed in the oviduct. These results suggest that beta3-adrenoceptors, mediating relaxation, are expressed in the human oviduct.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, Kuwait University, Kuwait, Kuwait.
authors.forename: Islam
authors.initials: I
authors.lastname: Khan
authors.forename: Alexander E
authors.initials: AE
authors.lastname: Omu
authors.forename: Tunde
authors.initials: T
authors.lastname: Fatinikun
authors.forename: Bindu
authors.initials: B
authors.lastname: Chandrasekhar
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Kadavil
authors.forename: Mabayoje A
authors.initials: MA
authors.lastname: Oriowo
mesh_terms: D058667:Adrenergic beta-3 Receptor Agonists; D058673:Adrenergic beta-3 Receptor Antagonists; D000328:Adult; D004305:Dose-Response Relationship, Drug; D004983:Ethanolamines / Q000494:pharmacology; D005187:Fallopian Tubes / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008875:Middle Aged; D009126:Muscle Relaxation / Q000187:drug effects; D010869:Pindolol / Q000031:analogs & derivatives / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis; D022702:Receptors, Adrenergic, beta-3 / Q000096:biosynthesis*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D058667:Adrenergic beta-3 Receptor Agonists; D058673:Adrenergic beta-3 Receptor Antagonists; D004983:Ethanolamines; D012333:RNA, Messenger; D022702:Receptors, Adrenergic, beta-3; C047975:cyanopindolol; C057368:BRL 37344; D011433:Propranolol; D010869:Pindolol; D007545:Isoproterenol