Corticotropic cell

Adrenocorticotropin hormone stimulates the adrenal cortex to release glucocorticoids and plays an important role in the stress response.

In addition to synthesis in the corticotropes, POMC is also synthesized in melanotroph cells, the arcuate nucleus of the hypothalamus, and melanocytes.

[3] POMC undergoes differential cleavage into various peptide hormones depending on the cell it is synthesized in; it also varies based on species.

CRH is a 41-amino-acid peptide hormone that is secreted by the parvocellular neurosecretory cells, which are found within the paraventricular nucleus of the hypothalamus.

[10] Once released by the hypothalamus, CRH travels through the hypophyseal portal system to the anterior pituitary, where it binds to G protein-coupled receptors on the corticotropic cell membrane and stimulates cAMP production.

ACTH released from the corticotropes binds to G protein-coupled receptors in the adrenal cortex, where it stimulates the production of glucocorticoids (primarily cortisol).

[13] Glucocorticoids released by the adrenal cortex inhibit production of CRH and ACTH, forming a negative feedback loop.

GR is a nuclear receptor that inhibits transcription of ACTH via a negative glucocorticoid recognition element (GRE) that binds cortisol on POMC DNA, but generally transcortin binds glucocorticoids (including cortisol, cortisone, deoxycortisone, and aldosterone) with high affinity and prevents this inhibition.

POMC is broken down into several peptide hormones via proteolytic cleavage in the corticotropic cells.
Corticotropes located in the anterior pituitary are stimulated by the hypothalamus to release ACTH, which then travels via the bloodstream to the adrenal cortex.