In the glucose regulatory system, the main two players are the pancreatic hormones insulin and glucagon. Insulin and glucagon act together to balance metabolism. The pancreas releases glucagon when blood sugar (glucose) level falls too low. Glucagon causes the liver to convert stored glycogen into glucose, which is released in the bloodstream. Glucagon raises blood glucose levels and insulin organizes the use of fuels for either storage or oxidation. Elevated glucose concentrations of glucose in blood stimulate the release of insulin, and insulin acts on cells throughout the body to stimulate uptake, storage and utilization of glucose.