Glucagon-like peptide 1: a new promising treatment for type 2 diabetes

Glucagon-like peptide 1 (GLP-1) is a gut-derived peptide hormone secreted from intestinal endocrine L-cells after a meal. GLP-1 is a powerful incretin hormone: it increases insulin response to oral glucose, and thus constitutes a potential target for the treatment of type 2 diabetes. The biological actions of GLP-1 have several insulinotropic effects including potentiation of glucosestimulated insulin secretion, enhancement of pancreatic ß-cell growth, and inhibition of glucagon release. GLP-1 also inhibits food intake and gastric emptying. Unlike other incretin hormones, GLP-1 retains its insulinotropic effect when administered to persons with type 2 diabetes. These antidiabetic effects of GLP-1 have led to intense interest in the use of the GLP-1 signaling system as a mechanism for the treatment of patients with type 2 diabetes. The GLP-1 receptor agonist Exendin-4 is now approved for the treatment of type-2 diabetes in U.S.A., and several degradation resistant GLP-1 analogues as well as agents that retard the degradation of native GLP-1 are in the clinical trials. In this mini review we summarize the recent advances in our understanding of the biology of GLP-1.