title: Fat-induced ileal brake in humans: a dose-dependent phenomenon correlated to the plasma levels of peptide YY.
abstract: BACKGROUND
  Upper gastrointestinal motility is regulated by the presence of nutrients in the distal gut. The present study evaluated whether lipid-induced ileal brake on gastric emptying (1) can be elicited by low fat concentrations; (2) is a dose-dependent phenomenon; and (3) is related to gastrointestinal peptide release.
  
  
  METHODS
  Seven patients were studied in the defunctionalized stage of total colectomy, on three separate occasions. On each study day, patients ate a meal labeled in the solid component; 30 minutes later, one of the following solutions was randomly infused into the ileal pouch: 0.9% saline, 2% oleic acid, and 20% oleic acid. Plasma concentrations of peptide YY (PYY), enteroglucagon, neurotensin, and motilin were measured.
  
  
  RESULTS
  Both oleic acid solutions slowed gastric emptying compared with saline (P < 0.001), the effect being dose dependent (P < 0.001). Ileal infusions did not modify neurotensin and enteroglucagon levels but induced a dose-dependent increase of PYY (P < 0.01) and a borderline decrease of motilin (P = 0.05) levels. Slower rates of gastric emptying were related to increased plasma concentrations of PYY (r = 0.615; P < 0.05).
  
  
  CONCLUSIONS
  This study shows that (1) the ileal brake on gastric emptying can be evoked by low doses of lipids in the distal ileum; (2) the delay of gastric emptying is related to the release of PYY; and (3) both phenomena are dose dependent.
authors.affiliation: Institute of Internal Medicine and Gastroenterology, S. Orsola-Malpighi Hospital, University of Bologna, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Pironi
authors.forename: V
authors.initials: V
authors.lastname: Stanghellini
authors.forename: M
authors.initials: M
authors.lastname: Miglioli
authors.forename: R
authors.initials: R
authors.lastname: Corinaldesi
authors.forename: R
authors.initials: R
authors.lastname: De Giorgio
authors.forename: E
authors.initials: E
authors.lastname: Ruggeri
authors.forename: C
authors.initials: C
authors.lastname: Tosetti
authors.forename: G
authors.initials: G
authors.lastname: Poggioli
authors.forename: A M
authors.initials: AM
authors.lastname: Morselli Labate
authors.forename: N
authors.initials: N
authors.lastname: Monetti
mesh_terms: D000328:Adult; D003082:Colectomy; D004305:Dose-Response Relationship, Drug; D005260:Female; D005746:Gastric Emptying / Q000502:physiology; D005769:Gastrointestinal Motility / Q000502:physiology*; D004763:Glucagon-Like Peptides / Q000097:blood / Q000502:physiology; D006801:Humans; D007082:Ileum / Q000502:physiology*; D008055:Lipids / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D009037:Motilin / Q000097:blood / Q000502:physiology; D009496:Neurotensin / Q000097:blood / Q000502:physiology; D019894:Peptide YY; D010455:Peptides / Q000097:blood* / Q000502:physiology; D013997:Time Factors
chemical_list: D008055:Lipids; D010455:Peptides; D019894:Peptide YY; D009496:Neurotensin; D009037:Motilin; D004763:Glucagon-Like Peptides