| First Author | Scrocchi LA | Year | 2000 |
| Journal | Diabetes | Volume | 49 |
| Issue | 9 | Pages | 1552-60 |
| PubMed ID | 10969840 | Mgi Jnum | J:64159 |
| Mgi Id | MGI:1888811 | Doi | 10.2337/diabetes.49.9.1552 |
| Citation | Scrocchi LA, et al. (2000) Elimination of glucagon-like peptide 1R signaling does not modify weight gain and islet adaptation in mice with combined disruption of leptin and GLP-1 action. Diabetes 49(9):1552-60 |
| abstractText | Leptin and glucagon-like peptide 1 (GLP-1) exhibit opposing actions in the endocrine pancreas. GLP-1 stimulates insulin biosynthesis, secretion, and islet growth, whereas leptin inhibits glucose-dependent insulin secretion and insulin gene transcription. In contrast, GLP-1 and leptin actions overlap in the central nervous system, where leptin has been shown to activate GLP-1 circuits that inhibit food intake. To determine the physiological importance of GLP-1 receptor (GLP-1R)-leptin interactions, we studied islet function and feeding behavior in ob/ob:GLP-1R(-/-) mice. Although GLP-1R actions are thought to be essential for glucose-dependent insulin secretion, the levels of fasting glucose, glycemic excursion after glucose loading, glucose-stimulated insulin, and pancreatic insulin RNA content were similar in ob/ob:GLP-1R(+/+) versus ob/ob:GLP-1R(-/-) mice. Despite evidence linking GLP-1R signaling to the regulation of islet neogenesis and proliferation, ob/ob:GLP-1R(-/-) mice exhibited significantly increased islet numbers and area and an increase in the number of large islets compared with GLP-1R(+/+) or (-/-) mice (P < -0.01 to 0.05). Similarly, growth rates and both shortand long-term control of food intake were comparable in ob/ob:GLP-1R(+/+) versus ob/ob:GLP-1R4(-/-) mice. Furthermore, leptin produced a similar inhibition of food intake in GLP-1R(-/-), ob/ob:GLP-1R(+/+), and ob/ob:GLP1R4(-/-) mice. These findings illustrate that although leptin and GLP-1 actions overlap in the brain and endocrine pancreas, disruption of GLP-1 signaling does not modify the response to leptin or the phenotype of leptin deficiency in the ob/ob mouse, as assessed by long-term control of body weight or the adaptive beta-cell response to insulin resistance in vivo. |
