Aldosterone Physiology

Aldosterone is created from cholesterol within the zona glomerulosa of the adrenal glands. It is controlled by the renin-angiotensin-aldosterone system, while the rest of the adrenal glands hormone production is controlled by adrenocorticotropic (ACTH) hormone. Aldosterone increases the expression of epithelial sodium channels in the distal tubule, resulting in sodium and water reabsorption and potassium secretion. It affects blood pressure through regulating the amount of sodium and extracellular fluid volume expansion. It also indirectly affects the excretion of hydrogen ions.

In addition, aldosterone has pleiotropic actions in the heart, vascular smooth muscle cells and kidney mediated by autocrine and paracrine effects from local aldosterone production. It acts on local mineralocorticoid receptors and promotes inflammation, fibrosis, and neo-vascularization.