ACTH

Adrenocorticotropic Hormone (ACTH) Test Description

Adrenocorticotropic hormone (ACTH) or corticotropin is a peptide hormone consisting of 39 amino acidsw. It is synthesized in the anterior pituitary as part of the pro-opiomelanocortin precursor molecule (POMC).

Under the influence of peculiar-tissue cleavage, ACTH and other related peptides are produced. ACTH stimulates the synthesis and secretion of glucocorticoidss (primarily cortisol) by the adrenal cortex.

The concentration of ACTH in the adrenal cortex is also increased

The concentration of ACTH fluctuates throughout the day - in the morning its level is highest, in the evening its level is low. For the interpretation of the resultss, as in the case of cortisol, it is necessary to know the time of collection of the material.

Clinical significance:

Determination of plasma ACTH is helpful in the diagnosis of rs Cushing's disease (ACTH hypersecretion), autonomic ACTH-producing pituitary adenomass (e.g., Nelson's syndrome), pituitary insufficiency with decreased ACTH secretion, and ectopic ACTH secretion syndrome.

Rconcurrent determination of ACTH and cortisol in functional tests is used to diagnose a sourceof glucocorticoid overproduction.

Similarly, the determination of ACTH can be helpful in the diagnosis of rdnic adrenal insufficiency (Addison's disease).

ACTH not produced by the pituitary gland is known as ectopic ACTH is often found in small-cellral lung cancer.

In rare cases, the appearance of ectopic ACTH can be caused by thymic tumors, pancreatic adenocarcinoma or bronchogenic carcinoma.