Alpha cell

Alpha cell (or α-cell) is a type of cell in the pancreas that produces and secretes the hormone glucagon. They are located in the islets of Langerhans.

Function

The primary function of alpha cells is to regulate blood glucose levels. When blood glucose levels are low, alpha cells release glucagon. Glucagon then signals the liver to convert stored glycogen into glucose, which is released into the bloodstream. This process is known as glycogenolysis.

Structure

Alpha cells are typically located on the outer rim of the islets of Langerhans. They make up approximately 20% of the total islet cell population. Alpha cells are distinguishable from other islet cells due to their unique granules containing glucagon.

Clinical significance

Abnormal alpha cell function can lead to a variety of medical conditions. Overproduction of glucagon can lead to a condition known as hyperglucagonemia, which can cause hyperglycemia (high blood sugar). Conversely, underproduction of glucagon can lead to hypoglycemia (low blood sugar). Alpha cells can also be affected in diabetes, particularly in type 1 diabetes where there is a loss of alpha cells along with beta cells.

See also

• Beta cell
• Delta cell
• Pancreatic islets