title: The multifaceted potential of glucagon-like peptide-1 as a therapeutic agent.
abstract: Glucagon-like peptide-1 (GLP-1), an intestinal gut hormone, is rapidly emerging as a new therapeutic agent for the treatment of diabetes mellitus. GLP-1, released from intestinal L-cells, is renowned for its potent stimulation of insulin biosynthesis and release from pancreatic b-cells. Exogenous administration of GLP-1 to subjects with type 2 diabetes results in the normalization of plasma glucose concentrations, in part, as a result of augmented glucose-stimulated insulin secretion. However, it is now recognized that GLP-1 has several other anti-diabetic actions that collectively improve the type 2 diabetic phenotype, and may also prove beneficial in the treatment of type 1 diabetes. These effects include the deceleration of gastric emptying and promotion of satiety, thereby reducing the availability of nutrients for absorption and reducing the requirement for insulin secretion. GLP-1 also reduces plasma glucose levels by suppressing glucagon secretion from pancreatic a-cells and potentially by improving insulin sensitivity in peripheral tissues. Further-more, GLP-1 upregulates expression of b-cell genes (GLUT2, glucokinase, insulin, and PDX-1) and promotes b-cell neogenesis and differentiation of ductal cells into insulin secreting cells. Although initial clinical trials indicate GLP-1 has excellent therapeutic potential, its relatively short-lived biological activity and delivery difficulties limit its appeal. Several approaches that are currently being explored to overcome these limitations include mobilizing endogenous GLP-1 release, preserving the biological activity of the native peptide, and developing GLP-1 analogues with extended durations of action.
authors.affiliation: Departments of Medicine and Physiology, University of Alberta-Edmonton, Alberta, Canada.
authors.forename: N T
authors.initials: NT
authors.lastname: Lam
authors.forename: T J
authors.initials: TJ
authors.lastname: Kieffer
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D002986:Clinical Trials as Topic; D003921:Diabetes Mellitus, Experimental / Q000188:drug therapy; D003924:Diabetes Mellitus, Type 2 / Q000188:drug therapy*; D004333:Drug Administration Routes; D005746:Gastric Emptying / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D005934:Glucagon / Q000378:metabolism / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use*; D052216:Glucagon-Like Peptide 1; D000067757:Glucagon-Like Peptide-1 Receptor; D006801:Humans; D007004:Hypoglycemic Agents / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use*; D007328:Insulin / Q000096:biosynthesis / Q000378:metabolism; D007333:Insulin Resistance; D000078790:Insulin Secretion; D007421:Intestine, Small / Q000378:metabolism; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism; D010446:Peptide Fragments / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use*; D011498:Protein Precursors / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use*; D051381:Rats; D018027:Receptors, Glucagon / Q000187:drug effects / Q000502:physiology; D012528:Satiety Response / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology
chemical_list: D001786:Blood Glucose; C000593833:GLP1R protein, human; C000593835:Glp1r protein, rat; D000067757:Glucagon-Like Peptide-1 Receptor; D007004:Hypoglycemic Agents; D007328:Insulin; D010446:Peptide Fragments; D011498:Protein Precursors; D018027:Receptors, Glucagon; D052216:Glucagon-Like Peptide 1; D005934:Glucagon