Glucagon: An Incomplete and Biased Review with Selected References

This review summarizes the biochemistry, mode of action, physiologic functions, and clinical usefulness of glucagon, with emphasis on its role as a mobilizer of glycogen and fat, when adequate amount of exogenous nutrients are unavailable (starvation, heavy exercise, neonatal state) or cannot be properly utilized (diabetes mellitus). The “anti-insulin” properties of glucagon and the lessons of comparative physiology are reviewed.