Neurotensin secretion in response to intraduodenal and intraileal administration of fat in dogs

Release of neurotensin from the small intestine in response to administration of fat directly into the duodenum and ileum was examined in conscious dogs. The present results show that: (1) intraduodenal administration of fat causes a biphasic release of neurotensin which is mediated, at least in part, by cholinergic mechanisms, and (2) both a fatty acid (sodium oleate) and a triglyceride, when infused directly into an isolated ileal loop, stimulate a significant release of neurotensin. Our findings indicate that release of neurotensin is triggered by mechanisms originating in the proximal small intestine and by a direct contact of nutrients with the ileal mucosa.