Radiolabeled glucagon-like peptide-1 analogues: a new pancreatic β-cell imaging agent.

Glucagon-like peptide-1 (GLP-1) is a potent antihyperglycemic hormone. It can induce glucose-dependent insulin secretion. GLP-1 has a short half-life of less than 2 min in vivo due to degradation by the dipeptidyl peptidase-IV. GLP-l analogues, such as exendin-4 and exendin-3, have similar biological activity but a longer in-vivo half-life. Pancreatic β-cells and pancreatic islet cell tumors highly express GLP-1 receptors. Hence, radiolabeled GLP-1 analogues play a potential role in imaging and radiation therapy of pancreatic islet cell tumors as well as in the monitoring of pancreatic β-cell transplantation.