glucagon

n. hormone formed in the pancreas

Glucagon is an important hormone involved in carbohydrate metabolism. Produced by the pancreas, it is released when the glucose level in the blood is low (hypoglycemia), causing the liver to convert stored glycogen into glucose and release it into the bloodstream. The action of glucagon is thus opposite to that of insulin, which instructs the body's cells to take in glucose from the blood in times of satiation.
See more at Wikipedia.org...

Glucagon /glu·ca·gon/ a polypeptide hormone secreted by the alpha cells of the islets of Langerhans in response to hypoglycemia or to stimulation by [more]Glucagon - Community and Resources

Noun
1. a hormone secreted by the pancreas; stimulates increases in blood sugar levels in the blood (thus opposing the action of insulin)
(hypernym) hormone, endocrine, internal secretion

n. glucagon, hormone formed in the pancreas