1: Mol Cell Endocrinol. 2007 Sep 30;276(1-2):18-23. Epub 2007 Jun 29. GLUT2 and the incretin receptors are involved in glucose-induced incretin secretion. Cani PD, Holst JJ, Drucker DJ, Delzenne NM, Thorens B, Burcelin R, Knauf C. Institut de Médecine Moléculaire de Rangueil, I(2)MR, IFR31, CHU Rangueil, BP 84225, 31432 Toulouse cedex 4, France; Unit of Pharmacokinetics, Metabolism, Nutrition and Toxicology, Université catholique de Louvain, Av. E. Mounier 73/69, 1200 Brussels, Belgium. Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are incretins secreted in response to oral glucose ingestion by intestinal L and K cells, respectively. The molecular mechanisms responsible for intestinal cell glucose sensing are unknown but could be related to those described for beta-cells, brain and hepatoportal sensors. We determined the role of GLUT2, GLP-1 or GIP receptors in glucose-induced incretins secretion, in the corresponding knockout mice. GLP-1 secretion was reduced in all mutant mice, while GIP secretion did not require GLUT2. Intestinal GLP-1 content was reduced only in GIP and GLUT2 receptors knockout mice suggesting that this impairment could contribute to the phenotype. Intestinal GIP content was similar in all mice studied. Furthermore, the impaired incretins secretion was associated with a reduced glucose-stimulated insulin secretion and an impaired glucose tolerance in all mice. In conclusion, both incretins secretion depends on mechanisms involving their own receptors and GLP-1 further requires GLUT2. PMID: 17681422 [PubMed - as supplied by publisher] Related Links GIP and GLP-1 as incretin hormones: lessons from single and double incretin receptor knockout mice. [Regul Pept. 2005] PMID:15780432 The incretins: a link between nutrients and well-being. [Br J Nutr. 2005] PMID:15877888 Enhanced glucose-dependent insulinotropic polypeptide secretion and insulinotropic action in glucagon-like peptide 1 receptor -/- mice. [Diabetes. 1998] PMID:9648827 Glucagon-like peptide-1 and control of insulin secretion. [Diabete Metab. 1995] PMID:8586147 Gluco-incretins control insulin secretion at multiple levels as revealed in mice lacking GLP-1 and GIP receptors. [J Clin Invest. 2004] PMID:14966573