Lab

Adrenocorticotropic Hormone

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Adrenocorticotropic Hormone, ACTH, Corticotropin, Serum ACTH

  • Physiology
  1. ACTH is a polypeptide synthesized and secreted by Basophil cells in the anterior pituitary
    1. Stimulation (releasing factors)
      1. Corticotropin Releasing Hormone (CRH, from Hypothalamus)
      2. Emotional or physical stress
        1. Sympathetic response to stress triggers hypothalamic release of CRH
    2. Inhibition by negative feedback loops
      1. Cortisol inhibits CRH release from Hypothalamus
      2. Cortisol inhibits ACTH release from pituitary
  2. Components
    1. Polypetide of 39 amino acids, encoded by the POMC gene in humans
  3. ACTH Effects (Adrenal Cortex stimulation)
    1. Cortisol release (Glucocorticoid, primary function)
    2. Other, less potent effects
      1. Aldosterone release (mineralcorticoid)
      2. Androgenic steroid release
  • Pathophysiology
  1. Cushing Disease
  2. Addison Disease
  • References
  1. Goldberg (2014) Clinical Physiology, Medmaster, Miami, p. 132-46