PPY belongs to the NPY family and is synthesized as a 95 aa polypeptide precursor in the pancreatic islets of Langerhans. It is cleaved into two peptide products; the active hormone of 36 aa and an icosapeptide of unknown function. The hormone acts as a regulator of pancreatic and gastrointestinal functions and may be important in the regulation of food intake. Plasma level of this hormone has been shown to be reduced in conditions associated with increased food intake and elevated in anorexia nervosa.