Adrenocorticotropic hormone (ACTH), also known as corticotropin (INN, BAN) (brand names Acortan, ACTH, Acthar, Acton, Cortigel, Trofocortina), is a polypeptide tropic hormone produced and secreted by the anterior pituitary gland. It is an important component of the hypothalamic-pituitary-adrenal axis and is often produced in response to biological stress (along with its precursor corticotropin-releasing hormone from the hypothalamus). Its principal effects are increased production and release of cortisol by the cortex of the adrenal gland. Primary adrenal insufficiency, also called Addison's disease, occurs when adrenal gland production of cortisol is chronically deficient, resulting in chronically elevated ACTH levels; when a pituitary tumor is the cause of elevated ACTH (from the anterior pituitary) this is known as Cushing's disease and the constellation of signs and symptoms of the excess cortisol (hypercortisolism) is known as Cushing's syndrome. Conversely, deficiency of ACTH is a cause of secondary adrenal insufficiency, often as a result of hypopituitarism. ACTH is also related to the circadian rhythm in many organisms.
Adrenocorticotropic hormone (ACTH), also known as corticotropin, is a cleavage product from a larger precursor proopiomelanocortin (POMC). This 39 amino acid-peptide hormone is produced in the anterior pituitary gland upon stimulation by the corticotropin releasing hormone from the hypothalamus in response to stress. It stimulates the secretion of steroid hormone, specifically glucocorticoids in the adrenal cortex by acting through a cell membrane receptor (ACTH-R). In mammals, the action of ACTH is limited to those areas of the adrenal cortex in which the glucocorticoid hormones cortisol (hydrocortisone) and corticosterone are formed. ACTH has little control over the secretion of aldosterone, the other major steroid hormone from the adrenal cortex.