Release of distal gut peptide YY (PYY) by fat in proximal gut depends on CCK

We tested the hypothesis that the release of PYY by fat confined to the proximal small intestine is dependent on CCK. Using a multi-fistulated model, plasma PYY levels were compared in 6 dogs after 60 mM oleate was perfused into the proximal one-half of the small intestine following i.v. administration of saline or devazepide, a CCK-A antagonist. Plasma PYY increased with fat (P < 0. 05), but plasma PYY level was lower following devazepide at 60 min and 90 min (P < 0.05). We conclude that CCK serves as a foregut signal linking fat in the proximal gut with the release of distal gut PYY.