121249-14-7

Diagnostic aid(adrenocortical insufficiency); diagnostic aid (Cushing’s syndrome); hormone (corticotropin-releasing).

The primary function of corticotropin-releasing factor (CRF), a hypothalamic 41-peptide, is the regulation of the release of adrenocorticotropin hormone (ACTH) from the anterior pituitary gland, which then stimulates the release of hydrocortisone from the adrenal gland. The human peptide (hCRF) and the similar sequence found in sheep (oCRF) have been prepared by synthesis. The ovine form of the hormone, however, has replaced the human form because of its longer half-life and greater potency; hCRF is no longer commercially available.
Usually, ACTH deficiency in humans is associated with a pituitary disorder rather than with a deficiency of CRF, and oCRF can be used to distinguish between pituitary hypersecretion of ACTH (Cushing's disease) and ectopic ACTH secretion, both of which are conditions that cause a hypersecretion of hydrocortisone. In the case of ectopic ACTH secretion, the administration of oCRF will elicit little to no response in the production of ACTH and hydrocortisone. Therefore, synthetic oCRF trifluoroacetate salt is marketed as a diagnostic agent for patients with ACTH dependent Cushing's syndrome.