Aldosterone and Mineralocorticoid Receptors

Physiologically, aldosterone is a homeostatic hormone, rising in response to sodium deficiency, potassium loading, and volume depletion to restore the status quo ante: it is also raised acutely but not chronically by adrenocorticotropic hormone (ACTH). Pathophysiologically, in primary aldosteronism (PA) aldosterone levels are inappropriately high for the subject's sodium/potassium/volume status, thus outside the normal feedback loop, and no longer homeostatic but causing widespread deleterious cardiovascular effects. Long thought to be a rare and relatively benign form of hypertension, patients with PA have much higher risk factors for cardiovascular disease than age-, sex-, and BP-matched essential hypertensives. The role of ACTH in aldosterone secretion has not received major attention, although recent studies suggest a major involvement in stress-related rather than homeostatic secretion, playing an additional, as yet unrecognized, causative role in PA.