Clinical implications of excess aldosterone output.

Abstract

Aldosterone is the most active corticosteroid secreted by the adrenal cortex in promoting sodium retention and elimination of potassium. In physiological amounts it is believed that aldosterone predominates in the control of sodium and potassium balance, while carbohydrate metabolism and various other functions are affected by hydrocortisone. Secretion of aldosterone and secretion of hydrocortisone by the human adrenal cortex appear to be regulated by distinctly different mechanisms. According to present concepts (Fig. 1) a neurohumoral substance secreted by the hy Hypothalamus Anterior Pituitary Adrenal Cortex Circulating Hydrocortisone Hypothalamus Diencephalon Anterior Pituitary Adrenal Cortex Aldosterone t Na Reabsorption K Reabsorption? Extrarenal Effects Extracellular Fluid Volume (? Blood Volume) Fig. 1. —Regulatory mechanisms for control of hydrocortisone and aldosterone secretion. Present concepts of regulation derived from available evidence. Broken arrows are used when supporting evidence is only suggestive. pothalamus acts upon the anterior pituitary gland to release adrenocorticotropin, which stimulates the adrenal cortex