Adrenocorticotropic hormone (ACTH)

ACTH is also known as the stress hormone because its levels rise during times of stress. Photo: iStock.com/Nomadsoul1

Definition

ACTH (corticotropin, INN name) is a peptide hormone composed of 39 amino acids. Of these 39 amino acids, only the first 24 (counting from the N-terminus) are necessary for biological activity. For therapeutic purposes, a chemically synthesized polypeptide (tetracosactide) containing these amino acids is therefore used. As a medication, the active ingredient tetracosactide is available on the market under the brand name Synacthen®.

ACTH is produced in the pituitary gland (hypophysis) and, after being released into the blood, stimulates the synthesis of the corticosteroid cortisol in the adrenal glands. ACTH release is subject to control (negative feedback) by cortisol and is stimulated by catecholamines. Since ACTH is released in increased amounts during stress, it is also referred to as a stress hormone. The release of ACTH in the pituitary gland and the subsequent release of cortisol follow a day-night rhythm.

Significance as a doping agent

The World Anti-Doping Agency (WADA) prohibits corticotropins under Group S2, “Peptide Hormones, Growth Factors, and Related Compounds,” in Section 3. This includes not only the use of ACTH but also that of the synthetic product (Synacthen®). This is comparable to the prohibited oral or intravenous use of glucocorticoids (see also Glucocorticoids).