Glucagon is a crucial hormone involved in glucose metabolism, secreted by the alpha cells of the pancreatic islets of Langerhans. It plays an essential role in maintaining blood glucose levels by promoting glycogenolysis and gluconeogenesis, particularly in fasting states. Its physiological function is counter-regulatory to insulin, preventing hypoglycemia. Beyond its metabolic effects, glucagon has emerging roles in cardiovascular function, lipid metabolism, and gastrointestinal motility. Clinically, glucagon is used in the management of severe hypoglycemia, glucagon stimulation tests, and as an adjunct in imaging studies. Recent advances have also explored its potential in obesity and non-insulin-dependent diabetes mellitus therapies. This article discusses glucagon’s biochemistry, physiological function, clinical applications, and therapeutic potential, emphasizing ongoing research and future directions.
