Corticotropin is a polypeptide hormone, also known as adrenocorticotropic hormone (ACTH), synthesized and stored in the anterior pituitary gland. Large amounts of corticotropin are released in response to any form of stress. Adrenocorticotropic hormone (ACTH) is a hormone that stimulates the production of cortisol. Cortisol is a steroid hormone made by the adrenal glands that is important for regulating glucose, protein, and lipid metabolism, suppressing the immune systems response, and helping to maintain blood pressure.