The synthetic version of a compound in lizard venom seems to complement insulin and help people with diabetes steady their sugar metabolism, a new study finds. The drug, called exendin-4, is a protein fragment that researchers originally isolated from Gila monster venom. Exendin-4 functions like a substance called glucagon-like protein-1, or GLP-1, which people secrete in their intestines. After a meal, the body releases GLP-1 to signal satiety and stimulate insulin-secreting beta cells in the pancreas.
Physician John Dupre of the University of Western Ontario in London, Ont., reported on eight type I diabetes patients getting an injection of exendin-4 or a placebo with their insulin shot at breakfast. All had better control of sugar concentrations in their blood during the morning when they got exendin-4.
It’s unclear how the drug achieves this effect, since type I diabetes patients have no functional beta cells. Instead of stimulating such cells, exendin-4 may regulate blood sugar by slowing the rate at which the stomach empties food into the intestines, Dupre speculates.