The purpose of glucagon is to raise blood sugar, primarily by promoting release of stored glucose in the liver. Human glucagon has been synthesized by recombinant DNA technology and is available in a dry powder form in the glucagon rescue kit. This is useful for rescue of unconscious diabetics from a severe state of hypoglycemia.
In healthy pancreatic function, glucagon production is initially suppressed by beta cell production of insulin and amylin when blood sugar is high, and then is later produced by low or falling blood sugar. The natural pancreatic function uses glucagon at the end of an insulin cycle to release glucose from the liver, with two advantages:
- to prevent low blood sugar, and
- to speed the overall insulin action by canceling the insulin tail.
If an artificial pancreas was to simulate the natural endocrine pancreas to the maximum extent, then insulin and amylin would be used at the beginning of an insulin cycle and glucagon would be used at the end of the insulin cycle.
Preliminary research with pigs who are given glucagon automatically is very promising, suggesting that most researchers will come around to seeing the benefits of incorporating glucagon into the artificial pancreas.