INTRALUMINAL LIPIDS MODULATE AVIAN GASTROINTESTINAL MOTILITY

Infusion of lipids into the ileum delays gastric emptying and intestin al transit time in some species. The aim of this study was to characte rize the actions of intraluminal lipid infusion on gastrointestinal el ectrical activity in chickens. Animals were prepared for electromyogra phy with chronic electrodes in stomach, duodenum, and small intestine. Two catheters were chronically placed in the esophagus and ileum to i nfuse equimolar doses of either oleic acid (OA) or triolein (TO). Both OA and TO, esophageally infused, inhibited the frequency of the gastr oduodenal cycle and increased the frequency of antiperistaltic spike b ursts in the duodenum. Ileal infusion of OA, but not of TO, produced t he same effects. Both esophageal and ileal OA infusion increased the d uration of the migrating myoelectric complex (MMC) and decreased the s peed of propagation of phase III. In conclusion, intraluminal infusion of lipids modulates gastrointestinal motility by decreasing the frequ ency of the gastric cycle, increasing duodenogastric refluxes, and elo ngating the MMC. These actions could delay gastric emptying and increa se transit time, which suggests the presence of an ''ileal brake'' mec hanism similar to that described in mammals.