Neurotensin decreases pepsin output and gastrointestinal motility in chickens

Abstract

Two experiments were conducted to determine the effect of neurotensin on gastric secretion and gastrointestinal motility in conscious chickens. Chickens were surgically fitted with a cannula to collect secretions from the proventriculus and strain gauge transducers sutured to the gizzard, duodenum, and ileum in order to detect contractions. Peripheral intravenous infusion of physiological levels of neurotensin inhibited pepsin output from the proventriculus, but had no effect on the volume or pH of gastric secretions. Neurotensin also inhibited both the frequency and strength of gastrointestinal contractions when compared to motility patterns following infusion of isotonic 0.9% (wt/vol) saline. The frequency of occurrence of small intestinal refluxes was not affected by neurotensin. These results coupled with our earlier work, which demonstrated that neurotensin is released by the presence of oleic acid in the duodenum, indicate that neurotensin may function as an enterogastrone released by lipids in the gastrointestinal tract of the chicken. This overall inhibitory effect of neurotensin on the avian gut indicates that it is involved in the postprandial regulation of digestion, especially lipid digestion.

Biology of the Gastrointestinal Tract in Poultry

“…The frequency of muscle contractions of the gizzard is depressed by pancreatic polypeptide in the chicken . Similarly, contractions of the gizzard are depressed in the presence of neurotensin (Degolier et al, 1997).…”

“…Pepsin secretion from the proventiculus is depressed in the presence of neurotensin (Degolier et al, 1997). Histamine antagonists reduce release of acid (Guinotte et al, 1993).…”

Molecular characterization of structure and tissue distribution of chicken neurotensin receptor

“…In addition, the release of NT has been shown to be in response to lipid perfusion in the chicken duodenum [17]. These findings suggest that NT is involved in the post-prandial regulation of digestion, especially for lipid digestion [13]. In this study, realtime PCR analysis revealed the expression of NTR1 mRNA in chicken GI tract such as the proventriculus, gizzard, duodenum, jejunum, ileum, cecum, and colon/rectum, with remarkably abundant levels in the colon/rectum.…”

“…It has been demonstrated that NT inhibits pepsin output from the proventriculus as well as the frequency and strength of contraction and motility of chicken GI tract in vitro and in vivo [13,33]. In addition, the release of NT has been shown to be in response to lipid perfusion in the chicken duodenum [17].…”

The effect on adipose tissue blood flow of isoenergetic meals containing different amounts and types of fat

“…Hormones involved in gut regulation may be mediators for this; for example, (Gln4)-neurotensin, which is released in response to fat in the small intestine, seems to be involved in the regulation of lipid digestion 6,7 and may act as a hormone affecting the regional deposition of fat postprandially by regulating ATBF. 8 Gut hormones which could be involved include gastric inhibitory polypeptide, cholecystokinin, somatostatin and glucagon-like peptide.…”