title: Gastric relaxation induced by glucagon-like peptide-2 in mice fed a high-fat diet or fasted.
abstract: Glucagon-like peptide-2 (GLP-2) is a nutrient-responsive gut hormone that increases the intestinal absorption. Exogenous GLP-2 also induces gastric fundus relaxation with possible implications for emptying rate or feeling of satiety. GLP-2 actions are mediated by GLP-2 receptor (GLP-2R), located on enteric neurons and myofibroblasts in murine gastrointestinal tract. Because it is not known whether changes in the endogenous GLP-2R levels occur in different nutritional states, we examined the GLP-2R gene and protein expression in gastric fundus from standard diet (STD)-fed, 12-h and 24-h fasted and re-fed, or high-fat diet (HFD)-fed mice and we analyzed the mechanical responses to exogenous GLP-2 in the stomach from different groups of animals. GLP-2 expression was examined using real-time reverse-transcription polymerase chain reaction and western blotting. The gastric mechanical activity from whole-organ was recorded in vitro as changes of intraluminal pressure. GLP-2R expression in fundic region from 12-h or 24-h fasted mice was reduced in comparison with STD-fed animals and returned to control values in re-fed mice, while it was increased in HFD-fed mice. The exogenous GLP-2 efficacy in inducing gastric relaxation, normalized to isoproterenol response, was decreased in stomach from fasted mice and it was increased in stomach from HFD-fed mice in comparison with STD-fed mice. In conclusion, the nutritional state influences GLP-2R expression in murine gastric preparations. The changes in the GLP-2R expression are associated with modifications of GLP-2 gastric relaxant efficacy. This could represent an adaptive response to reduced or increased nutrient intake.
authors.affiliation: Dipartimento di Scienze e Tecnologie Molecolari e Biomolecolari (STEMBIO), Università di Palermo, 90128 Palermo, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Rotondo
authors.forename: Antonella
authors.initials: A
authors.lastname: Amato
authors.forename: Sara
authors.initials: S
authors.lastname: Baldassano
authors.forename: Laura
authors.initials: L
authors.lastname: Lentini
authors.forename: Flavia
authors.initials: F
authors.lastname: Mulè
mesh_terms: D000818:Animals; D059305:Diet, High-Fat; D005215:Fasting / Q000502:physiology*; D005748:Gastric Fundus / Q000378:metabolism*; D053767:Glucagon-Like Peptide 2 / Q000378:metabolism*; D000067758:Glucagon-Like Peptide-2 Receptor; D007421:Intestine, Small / Q000378:metabolism*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018027:Receptors, Glucagon / Q000235:genetics / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D053767:Glucagon-Like Peptide 2; D000067758:Glucagon-Like Peptide-2 Receptor; D018027:Receptors, Glucagon