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Pituitary Hormones affecting the Adrenal Cortex - FAQs

The pituitary gland communicates to and regulates thethe adrenal glands primarily through  the hormone adrenocorticotropin (ACTH).

The Adrenocorticotropic Hormone (ACTH)

About 90% of the adrenal gland tissue consists of

  1. fasciculata (cortisol)
  2. the adrenal cortex: glomerulosa (aldosterone)
  3. reticularis (adrenal androgens)

This page discusses #1 and the hormonal relationship between the pituitary gland's production of ACTH and the adrenal gland's subsequent production of cortisol.

Cortisol is a vital hormone involved in carbohydrate and protein metabolism and control of the immune system (it dampens defense mechanisms - fight/flight, preventing their dangerous overactivity).

Within the pituitary gland a large precursor protein named proopiomelanocortin (POMC, "Big Mama") is synthesized by the pituitary gland and chopped into several fragments, of which ACTH is one of the results. Other parts of Big Mama are used to produce other hormones such as MSH, Melanocyte Stimulating Hormone, the hormone that darkens our skin.

Adrenocorticotropic hormone (ACTH), as its name implies, stimulates the adrenal cortex. More specifically, it stimulates secretion of glucocorticoids such as cortisol. ACTH is secreted from the pituitary gland in response to corticotropin-releasing hormone instructions from the hypothalamus. Another name for ACTH is corticotropin.

The hypothalamus is the body's regulator or thermostat of body systems and functions. The hypothalamus secretes the corticotropin-releasing hormone (CRH) in response to deviation from normal body system levels, in this case, lowered levels of cortisol in the blood. Cortisol blood levels often drop when the body undergoes various stresses.

Effects of Cortisol

  • Protects against hypoglycemia
  • Stimulates metabolism of glucose in liver
  • Stimulates muscle protein catabolism
  • Reduces insulin effects on glucose uptake
  • Enhances lipolysis (but paradoxically causes deposition of fat in trunk, cheeks)
  • Inhibits inflammation and immune response
  • Promotes bone loss
  • Inhibits clotting
  • Vasoconstriction, promotes hypertension

 Anti-inflammatory actions of Cortisol

  • Inhibit cytokine synthesis ( Some of these factors (Interleukin 1,2, 6) also stimulate cortisol secretion)
  • responds to infection: balances mediators of inflammation.
  • In pharmacologic form, is used to treat skin inflammation, autoimmune disorders, prevent graft or organ rejection

Effects of Cortisol Deficiency (Addison’s Disease)

  • Weakness, fatigue
  • Weight loss and anorexia
  • Hypotension (low blood pressure)
  • Inability to withstand "stress"
  • May be combined with aldosterone deficiency: (hyponatremia, hyperkalemia)

Effects of Cortisol Excess (Cushing’s syndrome)

  • Obesity
  • Muscular weakness
  • Hirsuitism (hairiness), bruising.
    • in women, menstrual disorders (from excess androgen secretion)
  • Hypertension
  • Osteoporosis


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