Human pancreatic polypeptide (hPP) is one such peptide, being released postprandially from F cells of the pancreatic islets depending on caloric load, food consumption and circadian rhythm. It is a C-terminally amidated 36 amino acid peptide with a characteristic hairpin-like pancreatic polypeptide (PP)-fold and acts at the Y4 receptor to induce satiety and delay gastric emptying and motility. Addition of the human pancreatic polypeptide (hPP) (10 nM-1 μM) results in a significant, dose-dependent reduction in both basal and stimulated release. Human pancreatic polypeptide (hPP) can also inhibit basal and stimulated NPY release with a pharmacological profile suggesting a role for Y4 presynaptic receptors.
