At least four neuropeptide Y receptor subtypes each with specific affinities to neuropeptide Y peptides, serve as regulators of mucosal function, gastrointestinal motility and secretion. Four receptors have been characterized to date; NPY1R (Larhammar D et al, 1992), NPY2R (Gerald C et al, 1995), NPY4R (Bard JA et al, 1995) and NPY5R (Parker EM and Xia L, 1999).
Neuropeptide Y peptides are also implicated as mediators in the pathogenesis of many gastrointestinal disorders, including malabsorption, short gut, inflammatory bowel diseases, and forms of pancreatitis. The three peptides are neuropeptide Y (NPY) (Minth CD et al, 1984), peptide YY (PYY) (Tatemoto K et al, 1988) and pancreatic peptide (PP) (Boel E et al, 1984).
Although each peptide can bind to any of the four receptors, they each have preferred receptors. NPY binds preferentially to NPY1R, PYY to NYP2R and PP to NYP4R.