Acute and chronic regulation of aldosterone production

Aldosterone is the major mineralocorticoid synthesized by the adrenal and plays an important role in the regulation of systemic blood pressure through the absorption of sodium and water. Aldosterone production is regulated tightly by selective expression of aldosterone synthase (CYP11B2) in the adrenal outermost zone, the zona glomerulosa. Angiotensin II (Ang II), potassium (K+) and adrenocorticotropin (ACTH) are the main physiological agonists which regulate aldosterone secretion. Aldosterone production is regulated within minutes of stimulation (acutely) through increased expression and phosphorylation of the steroidogenic acute regulatory (StAR) protein and over hours to days (chronically) by increased expression of the enzymes involved in the synthesis of aldosterone, particularly CYP11B2. Imbalance in any of these processes may lead to several disorders of aldosterone excess. In this review we attempt to summarize the key molecular events involved in the acute and chronic phases of aldosterone secretion.

► Aldosterone is the major mineralocorticoid produced by the adrenal zona glomerulosa.
► Glomerulosa cells are primarily regulated by angiotensin II, serum potassium and ACTH.
► Aldosterone synthesis involves two key phases, acute and chronic.
► Cholesterol delivery into mitochondria is the rate-limiting step in the acute phase.
► Aldosterone synthase (CYP11B2) is the rate-limiting step in the chronic phase.