A hormone secreted by the anterior portion of the pituitary gland and regulates hormone, primarily cortisol, secreted by the adrenal gland. OR A hormone made in the pituitary gland. Adrenocorticotropic hormone acts on the outer part of the adrenal gland to control its release of corticosteroid hormones. More adrenocorticotropic hormone is made during times of stress. Also called ACTH and corticotropin.