title: Expression of β-adrenoceptors in human lower esophageal sphincter.
abstract: OBJECTIVE
  Beta-adrenoceptor is considered to be an important modulator of smooth muscle function. It is widely present in the mammalian gastrointestinal tract and nervous system. The aim of this study was to explore the expression of 1-adrenoceptors (β1-AR, β2-AR, β3-AR) in sling fibers and clasp fibers from human lower esophageal sphincter (LES).
  
  
  METHODS
  Sling and clasp fibers from the LES were obtained from patients undergoing esophagogastrectomy; circular muscle strips from the esophagus and stomach were used as controls. Reverse transcription-polymerase chain reaction and western blotting were used to determine the expression of the three subtypes of β-adrenoceptors.
  
  
  RESULTS
  Messenger RNA and protein for three subtypes of β-adrenoceptors were all identified in the sling and clasp fibers of the LES. Expression was highest for β3-AR, then β1-AR and β2-AR in decreasing levels.
  
  
  CONCLUSIONS
  β1-AR, β2-AR, β3-AR can be detected in human lower esophageal sphincter and contribute to LES function.
authors.affiliation: Department of Thoracic Surgery, Fourth Hospital, Hebei Medical University, Shijiazhuang, China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Tao
authors.forename: Jun-Feng
authors.initials: JF
authors.lastname: Liu
mesh_terms: D000368:Aged; D015153:Blotting, Western; D049630:Esophageal Sphincter, Lower / Q000737:chemistry* / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis; D011943:Receptors, Adrenergic, beta / Q000032:analysis* / Q000235:genetics; D018342:Receptors, Adrenergic, beta-1 / Q000032:analysis; D018343:Receptors, Adrenergic, beta-2 / Q000032:analysis; D022702:Receptors, Adrenergic, beta-3 / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D012333:RNA, Messenger; D011943:Receptors, Adrenergic, beta; D018342:Receptors, Adrenergic, beta-1; D018343:Receptors, Adrenergic, beta-2; D022702:Receptors, Adrenergic, beta-3