title: Association between plasma ghrelin and motilin levels during MMC cycle in conscious dogs.
abstract: BACKGROUND
  Migrating motor complex (MMC) is well characterized by the appearance of gastrointestinal contractions in the interdigestive state. Gastric phase III contractions of MMC are regulated by motilin, but not ghrelin, in dogs. Ghrelin regulates feeding activity in dogs and rodents. It remains unclear how motilin and ghrelin interact during the MMC cycle in dogs.
  
  
  METHODS
  Four strain gauge transducers were implanted on stomach and intestine in 6 female dogs. To investigate the correlation between ghrelin and motilin, plasma motilin and acyl ghrelin (active type) levels were measured by radioimmunoassay (RIA) during MMC cycle.
  
  
  RESULTS
  The peak of plasma motilin levels was always observed at the period of gastric phase III contractions. The peak of ghrelin levels were followed 20-25 min after the peak of plasma motilin levels in 13 cases of 18 observations (72.2%). These were frequently observed at the early stage of gastric phase I contractions. In 3 of 16 observations (18.8%), the ghrelin peak was not associated with the motilin peaks. Immediately after the feeding, the interdigestive GI motor pattern was changed to the postprandial pattern. No significant increases of the plasma motilin levels and ghrelin levels were observed after the feeding.
  
  
  CONCLUSIONS
  This is the first demonstration showing the correlation between ghrelin and motilin levels during gastric MMC cycle in conscious dogs. As it is rather difficult to evaluate the hunger score in dogs, it remains unclear whether increased ghrelin levels after finishing gastric phase III contractions may mediate hunger sensation in dogs.
authors.affiliation: Department of Surgery, Medical College of Wisconsin and Zablocki VA Medical Center, Milwaukee, WI, USA.
authors.forename: Aaron
authors.initials: A
authors.lastname: Zietlow
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Nakajima
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Taniguchi
authors.forename: Kirk
authors.initials: K
authors.lastname: Ludwig
authors.forename: Toku
authors.initials: T
authors.lastname: Takahashi
mesh_terms: D000818:Animals; D003243:Consciousness / Q000502:physiology*; D004285:Dogs; D005260:Female; D054439:Ghrelin / Q000097:blood*; D009037:Motilin / Q000097:blood*; D016065:Myoelectric Complex, Migrating / Q000502:physiology*; D011863:Radioimmunoassay
chemical_list: D054439:Ghrelin; D009037:Motilin