How does glucagon raise blood glucose levels?
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Hormone
Many important physiological functions of vertebrates are controlled by steroid hormones.
Glucagon raises blood glucose levels primarily by acting on the liver to mobilize stored energy. It achieves this through two main biochemical processes:
- Glycogenolysis: Glucagon promotes the breakdown of glycogenāthe stored form of glucoseāinto glucose, which is then released into the bloodstream.12
- Gluconeogenesis: It stimulates the production of new glucose from non-carbohydrate sources, specifically amino acids and glycerol.12
Secreted by the alpha cells of the islets of Langerhans in the pancreas, glucagon acts as a counter-regulatory hormone to insulin. While insulin facilitates the storage of nutrients during the "fed" state, glucagon secretion increases during fasting or exercise to ensure that blood glucose concentrations remain within the narrow limits necessary to support the brain and other vital functions.12