Glucagon is released by alpha (α) cells located within the islets of Langerhans in the pancreas.
These specialized cells are crucial for maintaining glucose homeostasis in the body. When blood glucose levels drop too low (hypoglycemia), α cells secrete glucagon. This hormone travels to the liver, where it stimulates the breakdown of glycogen (stored glucose) into glucose, which then enters the bloodstream, raising blood sugar levels back to normal.
Factors Influencing Glucagon Release:
The release of glucagon from α cells isn't random. Several factors can influence it:
- Hypoglycemia: The primary trigger for glucagon release.
- Amino Acids: High levels of amino acids can stimulate glucagon secretion.
- Catecholamines: Epinephrine and norepinephrine, through β2-adrenergic receptors, can induce glucagon release.
- Free Fatty Acids: Increased free fatty acid levels can also trigger glucagon release.
Summary
In essence, the α cells of the islets of Langerhans are the sole cells responsible for producing and releasing glucagon. They play an essential role in regulating glucose metabolism, counteracting the effects of insulin and maintaining blood glucose balance.
