title: Beer congener stimulates gastrointestinal motility via the muscarinic acetylcholine receptors.
abstract: BACKGROUND
  Ethanol and alcoholic beverages are known to affect upper gastrointestinal motility in humans. Beer has been reported to accelerate gastric emptying compared with other beverages that contain the same ethanol concentrations. In this study, we investigated the mechanism that underlies the effects of beer congener on gastrointestinal motility.
  
  
  METHODS
  Gastric emptying activity was measured by means of movement of a semisolid test meal (0.05% phenol red/1.5% methylcellulose) in mice. To elucidate the mechanism for the effect of beer congener on gastrointestinal motility, we conducted receptor binding assays and contraction study by using longitudinal muscle from guinea pig ileum.
  
  
  RESULTS
  Beer congener (1 g/kg orally) enhanced gastric emptying of a semisolid meal in mice. The receptor binding assay revealed that beer congener bound to dopamine D2 receptor and 5-hydroxytryptamine (5-HT)3 receptor. These IC50 values were more than 5 mg/ml. However, beer congener bound to 5-HT2 receptor, 5-HT4 receptor, and muscarinic M3 receptor with IC50 values of 2, 0.9, and 2 mg/ml, respectively. Beer congener (0.05-2 mg/ml) induced the contraction of longitudinal muscle from guinea pig ileum in a dose-dependent manner. This effect was not affected by either tetrodotoxin (10(-6)M) or ketanserin (10(-7)-10(-5)M), an antagonist for the 5-HT2 receptor. On the other hand, 4-DAMP (10(-8)-10(-5)M), an antagonist for the muscarinic M3 receptor, inhibited the contraction of the longitudinal muscle induced by beer congener (2 mg/ml) dose dependently.
  
  
  CONCLUSIONS
  Beer congener stimulates gastrointestinal motility via the muscarinic M3 receptor.
authors.affiliation: Institute for Biological Safety Assessment, Suntory Limited, Mishima-gun, Osaka, Japan. Wataru_Fujii@suntory.co.jp
authors.forename: Wataru
authors.initials: W
authors.lastname: Fujii
authors.forename: Hisako
authors.initials: H
authors.lastname: Hori
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Yokoo
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Suwa
authors.forename: Haruo
authors.initials: H
authors.lastname: Nukaya
authors.forename: Kohtaro
authors.initials: K
authors.lastname: Taniyama
mesh_terms: D000818:Animals; D001515:Beer; D005769:Gastrointestinal Motility / Q000187:drug effects* / Q000502:physiology; D006168:Guinea Pigs; D007082:Ileum / Q000187:drug effects / Q000378:metabolism; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009130:Muscle, Smooth / Q000187:drug effects / Q000378:metabolism; D043587:Receptor, Muscarinic M3; D011976:Receptors, Muscarinic / Q000378:metabolism / Q000502:physiology*
chemical_list: D043587:Receptor, Muscarinic M3; D011976:Receptors, Muscarinic