Physiology · Endocrine System

Glucocorticoids: actions and regulation

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Definition

  • Glucocorticoids are adrenocortical steroids, chiefly cortisol, that regulate carbohydrate, protein and fat metabolism and suppress inflammation and immunity.
  • Cortisol secretion is controlled by the hypothalamo-pituitary-adrenal axis and shows a circadian rhythm that follows ACTH secretion.

Regulation of Secretion

  • CRH (hypothalamus) stimulates ACTH (anterior pituitary) to stimulate cortisol secretion from the adrenal cortex; cortisol negative feedbacks on both to inhibit CRH and ACTH.
  • CRH release is driven by limbic, pain-pathway, reticular and suprachiasmatic nucleus inputs.

Circadian (diurnal) variation in cortisol secretion