Effects of surgical manipulation of the intestine on peptide YY and its physiology.

PYY is a gastrointestinal hormone, mainly released from the distal intestine in response to intraluminal nutrients or via a neurohormonal pathway originating in the proximal intestine. Although there are several molecular forms of circulating PYY with different bioactivity, and further more than six subtypes of Y-receptors, the function is essentially inhibitory to digestive organs located upstream of the digestive tract. These inhibitory mechanisms are named jejunal, ileal and colonic brakes, and play an important supplementary role in adaptation following intestinal resection. When massive resection of the small intestine is performed, the release of PYY from the distal intestine increases, suppressing gastric acid secretion and motility of the gastrointestinal tract, and stimulating pancreatic secretion. After total colectomy, PYY release is reduced first due to reduction of PYY-containing cells, then gradually increases with time, contributing to adaptation of the digestive organs to the new condition.