Alpha cell

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  Alpha cell
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  Glucagon

Alpha Cell

Alpha cells are a type of endocrine cell found in the pancreas. They are primarily responsible for the production and secretion of the hormone glucagon, which plays a crucial role in the regulation of blood glucose levels.

Structure

Alpha cells are located in the islets of Langerhans, which are clusters of cells within the pancreas. The islets contain several types of cells, including beta cells, delta cells, and PP cells, each with distinct functions. Alpha cells are typically found on the periphery of the islets.

Function

The primary function of alpha cells is to produce and secrete glucagon. Glucagon is a peptide hormone that raises blood glucose levels by promoting glycogenolysis and gluconeogenesis in the liver. When blood glucose levels fall, such as between meals or during physical activity, glucagon is released to ensure a steady supply of glucose to the body, particularly the brain.

Regulation

The secretion of glucagon by alpha cells is regulated by several factors:

• Blood Glucose Levels: Low blood glucose levels stimulate glucagon release, while high levels inhibit it.
• Insulin: Insulin, secreted by beta cells, has an inhibitory effect on glucagon secretion.
• Amino Acids: Certain amino acids can stimulate glucagon release, which helps in maintaining glucose levels after protein-rich meals.
• Autonomic Nervous System: The sympathetic nervous system can stimulate glucagon secretion during stress or exercise.

Clinical Significance

Dysfunction of alpha cells can lead to metabolic disorders. For instance, in diabetes mellitus, the regulation of glucagon can be impaired, contributing to hyperglycemia. Understanding the role of alpha cells is crucial in developing treatments for such conditions.

Related Pages

• Beta cell
• Delta cell
• Pancreas
• Glucagon
• Insulin
• Islets of Langerhans