Peptide YY

Pancreatic Peptide YY3-36 is a peptide produced in the small intestine and colon that reduces appetite in response to feeding.

Description
Peptide YY3-36 (PYY) is a linear polypeptide consisting of 36 amino acids with structural homology to NPY and pancreatic polypeptide. PYY exerts its action through NPY receptors, inhibits gastric motility and increases water and electrolyte absorption in the colon. PYY may also suppress pancreatic secretion. It is secreted by the neuroendocrine cells in the ileum and colon in response to a meal, and has been shown to reduce appetite. Research has also indicated that PYY may be useful in removing aluminium (aluminum) accumulated in the brain.

Relevance to obesity
Leptin also reduces appetite in response to feeding, but obese people develop a resistance to leptin. In contrast, obese people secrete less PYY than normal people do, and in response to added PYY, they reduce their food intake.