peptide-yy and Intestinal-Neoplasms

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.

Topics: Colectomy; Humans; Intestinal Neoplasms; Intestine, Small; Models, Anatomic; Peptide YY; Time Factors

The frequency and distribution of polypeptide YY (PYY) and pancreatic polypeptide (PP) immunoreactive tumour cells of 14 small intestinal and of 27 rectal carcinoids were studied. All small intestinal and 14 rectal tumours were unreactive to both hormones. However, 13 rectal carcinoids contained a variable number of PP-immunoreactive cells. In four of these cases both PYY- and PP-immunoreactive cells were seen. The PP-immunoreactive cells greatly exceeded the number of PYY-immunoreactive cells. Two rectal carcinoids with PYY and PP immunoreactivities, but not the rest of the tumours, reacted also with an antiserum specific to the C-terminus of PP. This indicates that most PP immunoreactive rectal carcinoids lack the C-terminus sequence of the PP molecule.

Topics: Carcinoid Tumor; Histocytochemistry; Humans; Immunologic Techniques; Intestinal Neoplasms; Intestine, Small; Pancreatic Polypeptide; Peptide YY; Peptides; Rectal Neoplasms