title: Lack of direct effects of acyl ghrelin, des-acyl ghrelin, and obestatin on rat lower esophageal sphincter motility in vitro.
abstract: BACKGROUND
  Three ghrelin gene-derived peptides, acyl ghrelin, des-acyl ghrelin and obestatin, are implicated in the regulation of feeding, adipogenesis and glucose metabolism, as well as gut motility. The effects of ghrelin gene-derived peptides on lower esophageal sphincter motility, however, were unknown.
  
  
  METHODS
  We investigated the influence of acyl ghrelin, des-acyl ghrelin and obestatin on lower esophageal sphincter motility using the in vitro isolated muscle strip method. Both resting and carbachol-stimulated rat lower esophageal sphincters were tested.
  
  
  RESULTS
  Acyl ghrelin, des-acyl ghrelin and obestatin did not alter the resting tone of the lower esophageal sphincter, whereas carbachol increased the force of the muscle strips. Similarly, acyl ghrelin, des-acyl ghrelin and obestatin did not modify carbachol-induced stimulation of the lower esophageal sphincter, whereas papaverine significantly decreased the force of the muscle strips.
  
  
  CONCLUSIONS
  Since the contractile effects of carbachol and relaxant responses of papaverine on the lower esophageal sphincter were confirmed, our results demonstrate that acyl ghrelin, des-acyl ghrelin and obestatin have no direct effects on rat lower esophageal sphincter motility in vitro.
authors.affiliation: Division of Gastroenterology, Department of Medicine, Taipei Veterans General Hospital, Taipei, Taiwan, ROC.
authors.forename: Chih-Yen
authors.initials: CY
authors.lastname: Chen
authors.forename: Shih-Che
authors.initials: SC
authors.lastname: Huang
mesh_terms: D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D049630:Esophageal Sphincter, Lower / Q000187:drug effects* / Q000502:physiology; D005769:Gastrointestinal Motility / Q000187:drug effects; D054439:Ghrelin / Q000494:pharmacology*; D066298:In Vitro Techniques; D010208:Papaverine / Q000494:pharmacology; D051381:Rats
chemical_list: D054439:Ghrelin; C422650:ghrelin, des-n-octanoyl; D002217:Carbachol; D010208:Papaverine