Aldosterone

Aldosterone is a mineralocorticoid secreted by the zona glomerulosa of the adrenal cortex. Its primary mechanism of action is binding to mineralocorticoid receptors (MRs) within renal tubular epithelial cells, thereby promoting sodium ion (Na⁺) reabsorption and potassium ion (K⁺) excretion, while also increasing water reabsorption to maintain blood volume and blood pressure stability. Aldosterone secretion is regulated by the renin-angiotensin-aldosterone system (RAAS). When blood pressure falls, blood sodium levels decrease, or blood potassium levels rise, its release is stimulated. Excessive secretion can lead to hypertension and hypokalemia, whereas insufficient secretion may result in dehydration and hypotension.