title: Differential regulation of plasma obestatin and ghrelin by meal intake and the cholinergic system in lean, but not obese individuals.
abstract: BACKGROUND
  Obestatin is cosecreted with and stemming from the same precursor as ghrelin and is apparently involved in energy metabolism. Relatively little is known about the regulation of obestatin release.
  
  
  OBJECTIVE
  The regulation of obestatin release and obestatin-to-ghrelin ratios by meal intake and the cholinergic system were studied in lean and obese subjects.
  
  
  METHODS
  We conducted a randomized, double-blind, placebo-controlled, crossover study with 4 study days in eight obese (body mass index >30 kg/m(2)) and eight matched lean (body mass index <25 kg/m(2)) healthy subjects (two males and six females per group) at a University Clinical Research Unit.
  
  
  METHODS
  Atropine (1 mg iv) was administered alone and in combination with breakfast (550 kcal) intake, or placebo (isotonic saline) alone and in combination with breakfast.
  
  
  METHODS
  We measured plasma obestatin and obestatin/ghrelin ratios.
  
  
  RESULTS
  Both obestatin and ghrelin/obestatin ratios decreased significantly from baseline by either atropine or meal intake in lean individuals, with the two effects adding up on the combined atropine/breakfast day. In contrast, there were no statistically significant differences in obese subjects, who also showed significantly greater association between ghrelin and obestatin values than their lean counterparts.
  
  
  CONCLUSIONS
  Obestatin and ghrelin release is differentially regulated by meal intake and the cholinergic system in lean individuals. This regulation is impaired in obesity.
authors.affiliation: Department of Clinical Endocrinology and Metabolism, University Clinics of Medicine III, Medical University of Vienna, Vienna, Austria. Christina.maier@meduniwien.ac.at
authors.forename: Christina
authors.initials: C
authors.lastname: Maier
authors.forename: Michaela
authors.initials: M
authors.lastname: Riedl
authors.forename: Greisa
authors.initials: G
authors.lastname: Vila
authors.forename: Michael
authors.initials: M
authors.lastname: Wolzt
authors.forename: Martin
authors.initials: M
authors.lastname: Clodi
authors.forename: Bernhard
authors.initials: B
authors.lastname: Ludvik
authors.forename: Anton
authors.initials: A
authors.lastname: Luger
mesh_terms: D000328:Adult; D001285:Atropine / Q000008:administration & dosage / Q000494:pharmacology; D002799:Cholinergic Fibers / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D004435:Eating / Q000502:physiology*; D005260:Female; D054439:Ghrelin / Q000097:blood*; D006801:Humans; D008297:Male; D009765:Obesity / Q000097:blood* / Q000378:metabolism; D010275:Parasympathetic Nervous System / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D010276:Parasympatholytics / Q000008:administration & dosage / Q000494:pharmacology; D036361:Peptide Hormones / Q000097:blood*; D010919:Placebos; D013851:Thinness / Q000097:blood* / Q000378:metabolism
chemical_list: D054439:Ghrelin; D010276:Parasympatholytics; D036361:Peptide Hormones; D010919:Placebos; C505799:obestatin, human; D001285:Atropine