title: Peptide YY, neuropeptide Y and corticotrophin-releasing factor modulate gastrointestinal motility and food intake during acute stress.
abstract: BACKGROUND
  Peripheral neuropeptide Y (NPY) provides protection against the endocrine, feeding and gastrointestinal (GI) responses to stress; however, it is not yet established how it interacts with corticotrophin-releasing factor (CRF) to mediate these effects. Peptide YY (PYY) also has significant roles in GI motility and food intake but little is known about its role in stress responses.
  
  
  METHODS
  Upper GI transit, fecal pellet output (FPO) and feeding responses, and the role of CRF1 receptors, during restraint or a novel environment stress, were ascertained in PYY-/-, NPY-/- and wild type (WT) mice, with CRF and the CRF1 antagonist, antalarmin, injected intraperitoneally.
  
  
  RESULTS
  Upper GI transit and FPO were significantly increased in PYY-/- mice during restraint stress. Exogenous CRF increased defecation during placement in a novel environment in WT mice through CRF1 , while CRF1 blockade reduced defecation in WT and NPY-/- mice but had no effect in PYY-/- mice. In addition, CRF1 blockade had no effect on upper GI transit in WT mice, or on food intake in PYY-/- or NPY-/- mice, but it significantly increased food intake in WT mice.
  
  
  CONCLUSIONS
  Endogenous NPY appears to inhibit the colonic motor response induced by CRF1 activation, unlike PYY, while both peptides are required for CRF1 modulation of feeding behavior during stress. Overall, these results provide new insights into the mechanism by which PYY and NPY affect stress responses.
authors.affiliation: King's College London, Institute of Psychiatry, Psychology & Neuroscience, London, UK.
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Forbes
authors.forename: Helen M
authors.initials: HM
authors.lastname: Cox
mesh_terms: D000818:Animals; D003346:Corticotropin-Releasing Hormone / Q000502:physiology*; D005247:Feeding Behavior / Q000502:physiology*; D005769:Gastrointestinal Motility / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009478:Neuropeptide Y / Q000502:physiology*; D019894:Peptide YY / Q000502:physiology*; D012149:Restraint, Physical; D013315:Stress, Psychological / Q000503:physiopathology*
chemical_list: D009478:Neuropeptide Y; D019894:Peptide YY; D003346:Corticotropin-Releasing Hormone
keywords: acute stress; corticotrophin-releasing factor; food intake; gastrointestinal and colonic function; neuropeptide Y; peptide YY