see also:

• hormones
• angiotensin
• corticosteroids

• ACTH (aka corticotropin) is a polypeptide hormone secreted by the anterior pituitary gland
• its main actions are to increase synthesis and secretion of corticosteroids from the zona fasciculata of the adrenal cortex (via MC2R ACTH receptor) as part of the biological stress response
• ACTH also has a role in bone physiology, especially in osteoblasts
• half-life of ACTH in human blood is ~ 10 minutes
• impaired secretion of ACTH is a cause of secondary adrenal insufficiency
• excessive secretion of ACTH due to a pituitary tumour or ectopic production such as from small cell tumours of lung results in Cushing's syndrome