Glucagon-like Peptide-1, Exendin and Insulin Sensitivity
Glucagon-like peptide-1 (GLP-1), secreted from intestinal mucosa in response to nutrients, has been proposed as a therapy for treatment of type 2 diabetes, type 1 diabetes and obesity. Exendin-4 from the salivary secretions of the Gila monster shares many biological actions with GLP-1, but has superior pharmaceutical properties. A part of the rationale proposed for use of this class of agent has been an insulin-sensitizing effect. This chapter reviews preclinical and clinical evidence for the proposition that GLP-1 (either exogenous peptide or the endogenous hormone), GLP-1 analogs, or exendin-4 may alter insulin sensitivity. Most data have been obtained using GLP-1 and exendin-4. This chapter will focus upon studies using those peptides.