Exendin-4 (exenatide), a 39-amino acid peptide originally isolated from the salivary glands of the Gila monster (Heloderma suspectum), differs from exendin-3 only in two positions close to the N-terminus. Application of exenatide causes an increase in acinar cAMP without stimulating amylase release. As an incretin mimetic, exenatide acts as agonist of the glucagon-like peptide-1 (GLP-1) receptor. As GLP-1, though with prolonged activity, exenatide augments the postprandial production of insulin and suppresses secretion of glucagon. For this reason, exenatide has found use as a medication of diabetes II.