Gut peptide signaling in the controls of food intake.

During a meal and after a meal, ingested nutrients alter the release of a variety of gut peptides that have the potential to modulate food intake. Such feedback peptide signaling can be conceptualized as having three outcomes: meal termination, inhibitory modulation of intake in subsequent meals, and orexigenic modulation. Cholecystokinin, pancreatic glucagons, and amylin are examples of peptides involved in meal termination. They are released rapidly with the onset of feeding and have short durations of action. Peptide YY(3-36) and glucagon-like peptide 1 are peptides for which longer-term feeding inhibitory actions have been proposed. They are released from the distal intestine and have longer durations of actions. Ghrelin is a gastric peptide that stimulates food intake after its exogenous administration. Plasma ghrelin levels fall with feeding and rise with food deprivation. All of these gut peptides have vagal or dorsal hindbrain mediation. Their potential as targets for the development of anti-obesity treatments is under study.