Glucagon-like peptide-1(1-37) can enhance blood glucose homeostasis in mice.

Glucagon-like peptide-1 (GLP-1) is produced by the posttranslational processing of proglucagon and acts as a regulator of various homeostatic events. No blood glucose regulation role of GLP-1(1-37) has previously been identified. However, our findings in this study clearly showed that GLP-1(1-37) could lower blood glucose levels both in normal and diabetic mice. In vitro stability analysis demonstrated that GLP-1(1-37) was more stable than GLP-1(7-37), with 94.7% of the initial amount of peptide left after a 4h exposure to mouse serum. Moreover, GLP-1(1-37) was confirmed to be a highly potent agonist of the GLP-1 receptor (GLP-1R) by measuring the expression of the luciferase reporter gene expression in transiently transfected human embryonic kidney (HEK293) cells. Unlike the glucose lowering effect of GLP-1(7-37), the glucose-lowering effect of GLP-1(1-37) could not be blocked by the GLP-1R antagonist exendin(9-39), suggesting that GLP-1(1-37) might activate the GLP-1R via a different mechanism. Therefore, our findings suggest that GLP-1(1-37) could be a potential therapeutic drug for the treatment of type 2 diabetes in the future.