adrenocorticotrophin

Adrenocorticotrophin, also known as adrenocorticotropic hormone or ACTH, is a polypeptide hormone produced and secreted by the anterior pituitary gland. Its primary function is to stimulate the adrenal cortex, the outer layer of the adrenal glands, to produce and release corticosteroids. These corticosteroids include glucocorticoids, such as cortisol, and mineralocorticoids, such as aldosterone.

The secretion of ACTH is regulated by corticotropin-releasing hormone (CRH), which is released from the hypothalamus in the brain. CRH stimulates the pituitary gland to produce and release ACTH. In turn, ACTH travels through the bloodstream to the adrenal cortex, where it binds to specific receptors and triggers a cascade of intracellular events leading to corticosteroid synthesis and secretion.

Cortisol, a major corticosteroid, plays a crucial role in regulating metabolism, suppressing inflammation, and responding to stress. Aldosterone is essential for maintaining electrolyte balance and blood pressure. The feedback mechanism involving ACTH, CRH, and corticosteroids is a vital part of the hypothalamic-pituitary-adrenal (HPA) axis, which helps maintain homeostasis in the body. Abnormal levels of ACTH can indicate various endocrine disorders, such as Cushing's disease or Addison's disease.