mineralocorticoid

mineralocorticoid /min·er·alo·cor·ti·coid/ (min?er-il-o-kor´ti-koid)

1. any of the group of corticosteroids, principally aldosterone, primarily involved in the regulation of electrolyte and water balance through their effect on ion transport in epithelial cells of the renal tubules, resulting in retention of sodium and loss of potassium. Cf. glucocorticoid.

2. of, pertaining to, or resembling a mineralocorticoid.

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min·er·al·o·cor·ti·coid (mnr--l-kôrt-koid)

n.

Any of a group of steroid hormones that are secreted by the adrenal cortex and regulate the balance of water and electrolytes in the body.

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mineralocorticoid

any of a group of hormones elaborated by the cortex of the adrenal gland, so called because of their effects on sodium, chloride and potassium concentrations in the extracellular fluids. They are the adrenocortical hormones that are essential to the maintenance of adequate fluid volume in the interstitial and intravascular fluid compartments, normal cardiac output and adequate levels of blood pressure. Without sufficient supply of the mineralocorticoids, fatal shock from diminished cardiac output can occur very quickly.

The principal mineralocorticoid is aldosterone, which accounts for most of the activities of this group of hormones. The primary effects of the mineralocorticoids are increasing the reabsorption of sodium and the secretion of potassium in the renal tubules. Secondary effects are related to the reabsorption of water, serum levels of sodium and potassium, anion reabsorption and secretion of hydrogen ions. The net result of these activities is maintenance of fluid and electrolyte balance and, therefore, adequate cardiac output.