| First Author | Miki T | Year | 2005 |
| Journal | Diabetes | Volume | 54 |
| Issue | 4 | Pages | 1056-63 |
| PubMed ID | 15793244 | Mgi Jnum | J:105208 |
| Mgi Id | MGI:3614321 | Doi | 10.2337/diabetes.54.4.1056 |
| Citation | Miki T, et al. (2005) Distinct effects of glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 on insulin secretion and gut motility. Diabetes 54(4):1056-63 |
| abstractText | Glucose-induced insulin secretion from pancreatic beta-cells depends critically on ATP-sensitive K(+) channel (K(ATP) channel) activity, but it is not known whether K(ATP) channels are involved in the potentiation of insulin secretion by glucose-dependent insulinotropic polypeptide (GIP). In mice lacking K(ATP) channels (Kir6.2(-/-) mice), we found that pretreatment with GIP in vivo failed to blunt the rise in blood glucose levels after oral glucose load. In Kir6.2(-/-) mice, potentiation of insulin secretion by GIP in vivo was markedly attenuated, indicating that K(ATP) channels are essential in the insulinotropic effect of GIP. In contrast, pretreatment with glucagon-like peptide-1 (GLP-1) in Kir6.2(-/-) mice potentiated insulin secretion and blunted the rise in blood glucose levels. We also found that GLP-1 inhibited gut motility whereas GIP did not. Perfusion experiments of Kir6.2(-/-) mice revealed severely impaired potentiation of insulin secretion by 1 nmol/l GIP and substantial potentiation by 1 nmol/l GLP-1. Although both GIP and GLP-1 increase the intracellular cAMP concentration and potentiate insulin secretion, these results demonstrate that the GLP-1 and GIP signaling pathways involve the K(ATP) channel differently. |
