Peptide YY (PYY) is a polypeptide that is released postprandially in proportion to meal energy content by endocrine L cells in the ileum and colon in order to regulate appetite. PYY, along with neuropeptide Y (NPY; ), inhibits gastrointestinal motility and electrolyte secretion, which is thought to indicate satiety through a potent feedback signal on hypothalamic circuits. Upon release, PYY is cleaved to PYY (3-36), which is a preferred agonist at presynaptic inhibitory type 2 NPY autoreceptors (EC50 = 9.7 nM in human colon mucosa). PYY (3-36) has been associated with dose-dependent weight loss in various obesity models including ob/ob mice, diet-induced obese mice, and non-diabetic fatty Zucker rats.
