Pituitary adrenocorticotropic hormone release pathway (ACTH release pathway)

The pituitary ACTH release pathway is the central endocrine mechanism for regulating the body's response to stress via the hypothalamic-pituitary-adrenal (HPA) axis (StatPearls, NBK500031). It begins in the hypothalamus with the secretion of corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP) into the hypophyseal portal system (StatPearls, NBK541076). These secretagogues bind to specific G protein-coupled receptors, primarily CRHR1 and AVPR1B, on the surface of pituitary corticotroph cells, stimulating the synthesis and proteolytic processing of pro-opiomelanocortin (POMC) into adrenocorticotropic hormone (ACTH) (NIH, PMC3181830). Once released into the bloodstream, ACTH acts on the melanocortin 2 receptor (MC2R) in the adrenal cortex to induce the synthesis and secretion of glucocorticoids, primarily cortisol (PubMed, 16150944). The pathway is governed by a robust negative feedback mechanism where circulating cortisol inhibits the release of both CRH and ACTH to maintain physiological homeostasis (Journal of Endocrinology, 2017). Pathological overactivity of this pathway, often due to a pituitary adenoma, results in Cushing's disease, while underactivity leads to secondary adrenal insufficiency (NIH, PMC3181830). Therapeutic strategies targeting this pathway include somatostatin analogs like pasireotide and dopamine agonists like cabergoline to modulate ACTH levels in clinical contexts such as Cushing's disease (PubMed, 22397652).

Other names

HPA axisCorticotropin release pathwayPituitary-adrenal axis signaling

Modulation of ACTH secretion through antagonism of CRH or vasopressin receptors, or agonism of somatostatin or dopamine receptors on pituitary corticotrophs.