The ileal brake is an intraluminal nutrient-triggered feedback control from the distal to the proximal gut with fat being the most potent trigger. Peptide YY (PYY) is one of the hormonal mediators... Show moreThe ileal brake is an intraluminal nutrient-triggered feedback control from the distal to the proximal gut with fat being the most potent trigger. Peptide YY (PYY) is one of the hormonal mediators of the ileal brake. Effects of the fat induced ileal brake on proximal small intestine, postprandial gallbladder motility and hormone release are qualitatively and quantitatively different from those evoked by the fat induced jejunal brake. Activation of the ileal brake reduces gallbladder emptying especially in the late postprandial phase. It not clear wherether this action is hormonally mediated through PYY release. Ileal brake induced satiety and proximal gastric relaxation are not mediated through PYY release. In order to produce a significant effect on satiety and food intake the dose of exogenous PYY infusion must probably be in the supraphysiological range. Activation of the ileal brake with subsequent PYY release in malabsorptive diseases is most likely secondary, resulting from malabsorption rather than primarily due to the underlying disease. The findings that laxative induced malabsorption activates the ileal brake mechanism in healthy subjects and that pancreatic enzyme supplementation normalises antroduodenal motility and postprandial plasma PYY secretion in chronic pancreatitic patients with exocrine pancreatic secretion are clear evidence supporting this concept. Show less
