Glucocort: Mineralocorticoid activity
Basic, Organ-Based and Clinical Sciences
The adrenal cortex produces several classes of hormones, each derived from a cholesterol precursor. Glucocorticoids are hormones that promote gluconeogenesis and assist in the metabolism of energy sources, as well as mitigate the inflammatory cascade and delay bone formation. Production of glucocorticoids increases in response to ACTH release from the pituitary, which is released when stimulated by CRH from the hypothalamus. Cortisol levels are at their highest immediately after awakening. Trauma, surgery, exercise, and any psychological or physiological stressor can trigger ACTH and thus glucocorticoid release.
Mineralocorticoids serve the purpose of regulating the body’s fluid balance by controlling salt concentration. Among the mineralocorticoids, aldosterone has the greatest potency. The renin-angiotensin-aldosterone cascade regulates aldosterone levels in response to fluid status and serum potassium levels. Renin is produced when low perfusion pressures or an increased sympathetic tone is sensed. Aldosterone acts on the collecting duct and distal convoluted tube, leading to conservation of sodium and excretion of potassium. Outside of the kidney, aldosterone acts on the distal colon and sweat glands, also to preserve sodium levels. Retention of sodium leads to fluid retention and helps to preserve intravascular volume.
The relative glucocorticoid/mineralocorticoid potency of commonly administered steroids appear in the table below.