Elevation of Plasma Peptide YY and Pancreatic Juice Hypersecretion Following Massive Small Bowel Resection in the Rat.

Abstract

To clarify a physiological role of endogenous peptide YY(PYY) on pancreatic exocrine secretion, gastrointestinal transit and bile flow, a hyper-PYY-emia model was constructed by performing a massive small bowel resection using rats. (1) 75% resection of the small intestine was performed at its distal side. Two weeks after surgery, these rats were fed a liquid meal, and intestinal transit of contents was observed and plasma PYY and secretin concentrations were measured by radioimmunoassay. (2) Two weeks after the same surgery, a liquid meal was infused into the duodenum, and both pancreatic juice and bile were collected separately under general anesthesia. Transit of the intestinal contents from the pyloric ring, plasma CCK concentrations, pancreatic juice flow, amylase output, and bile flow were determined. Hyper-PYY-emia occurred following surgery both at fasting and after feeding, accompanied by retardation of gastrointestinal transit, increase of pancreatic juice flow and decrease of bile flow. Plasma secretin levels were elevated slightly, while CCK levels remained unchanged. In conclusion, massive small bowel resection is a useful model to induce hyper-PYY-emia in rats. It is considered that, in a malnutritional state after small intestinal resection, a colonic regulatory mechanism, via humoral factors such as PYY, participates in the feedback regulation of proximal intestinal as well as of pancreatic function.

Peptide YY induces enterocyte proliferation in a rat model with total enteral nutrition after distal bowel resection

“…In the present study, we found that with TEN, distal bowel resection also results in significant increases in the parameters of enterocyte proliferation. Massive bowel resection reserving distal bowel increases the plasma levels of PYY compared with sham rats [8,9]. These studies suggest that PYY seems to play an important role together with other neurohormonal factors to induce enterocyte proliferation.…”

“…This unique distribution makes PYY an ideal candidate for hormonal regulation of upper gastrointestinal function. After massive intestinal resection reserving distal bowel, plasma PYY levels in rats increased markedly after feeding, reaching their peak at 1 h and remaining at higher levels compared to the control (non-surgery) group for the following 5 h [8]. The increase in plasma PYY levels was owing to the reservation of part of the distal small intestine and colon.…”

“…It is released from L cells, which are mainly distributed in the lower small intestine and colon, in response to the presence of intraluminal nutrients [5][6][7]. In rats after massive intestinal resection reserving distal bowel, plasma PYY levels increased markedly after feeding [8]. Within days of intestinal resection, plasma PYY was raised and that this rise correlated with crypt cell production rate (CCPR) [3,9].…”

“…Many studies have shown that after massive intestinal resection reserving distal bowel, plasma PYY levels increased markedly both during fasting and after feeding [8,9]. The increase in plasma PYY levels after massive intestinal resection was owing to the reservation of the distal bowel (such as the lower small intestine and colon), where most of the L cells are distributed.…”

Grundlagen der zentralen Körpergewichtsregulation

“…An Mäusen konnte gezeigt werden, dass peripher verabreichtes PYY (3-36) zu einer moderaten Reduktion der Nahrungsaufnahme und leichtem Gewichtsverlust führt [14]. Dieser Sattheit vermittelnde Effekt ist auch in normalund übergewichtigen Menschen nachzuweisen [15] und wird zudem von der Beobachtung gestützt, dass ein Anstieg der Plasmawerte von PYY nach Ileumresektion ebenfalls mit Gewichtsverlust assoziiert werden konnte [16].…”