ACTH

Abbreviation for: Adrenocorticotropic hormone
Synonym: corticotropin, corticotropic hormone, adrenocorticotropin
German: ACTH

1 Definition

ACTH is a hormone that is synthesized in the anterior lobe of the pituitary gland, regulating the adrenal function.

2 Structure

The peptide hormone ACTH consists of 39 amino acids, whereof only the first 24 are important for the physiological effects.

3 Physiology

ACTH is generated in the basophilic cells of the anterior lobe of the pituitary gland under the influence of the corticotropin-releasing hormone (CRH) from the hypothalamus. It stimulates the adrenal cortex to synthesize glucocorticoids, and exerts an indirect influence on the production of insulin. The secretion of ACTH is subject to a circadian rhythm, its concentration in the morning is significantly higher than in the evening.

4 Pathology

The production or secretion of ACTH can be impaired in various diseases.
Elevated ACTH values result eg. from cold, stress, adrenal insufficiency, Cushing's disease and paraneoplastic syndrome, reduced levels from Sheehan's syndrome or tumors of the pituitary gland.
An ACTH deficiency leads to atrophy of the adrenal cortex.