Role of Glucocorticoids in Normal Function

The primary glucocorticoid released in humans is cortisol (also known as hydrocortisone). Cortisol synthesis and secretion are under the control of specific hypothalamic and pituitary hormones.7,24 31 Corticotropinreleasing hormone (CRH) from the hypothalamus stimulates the release of adrenocorticotropic hormone (ACTH) from the anterior pituitary. ACTH travels in the systemic circulation to reach the adrenal cortex, where it stimulates cortisol synthesis. Cortisol then travels in the bloodstream to various target tissues to exert a number of physiologic effects (see Physiologic Effects of Glucocorticoids, later). 

In addition to their normal circadian release, glucocorticoids are also released in response to virtually any stressful stimulus. For instance, trauma, infection, 

FIGURE 29-2 Negative feedback control of glucocorticoid synthesis. Cortisol limits its own synthesis by inhibiting the release of corticotropin-releasing hormone [CRH] from the hypothalamus and adrenocorticotropic hormone [ACTH] from the anterior pituitary. 

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