Aldosterone

Aldosterone is a steroid hormone synthesized in the mid-section of the adrenal cortex of the adrenal gland. It is the sole endogenous member of the class of mineralocorticoids. It helps regulate the body's electrolyte balance by acting on the mineralocorticoid receptor (MR).

Unlike neuroreceptors , classic steroid receptors are located inside of cells. The aldosterone/MR receptor binds to hormone response elements (HRE) of the DNA that alter protein synthesis and the transcription of messenger RNA, including serum and glucocorticoid-induced kinase , channel-inducing factor , K-ras2A , and three subunits of the epithelial sodium channel . These genes are important for transepithelial sodium transport .

Aldosterone is synthesized in reaction to increases of angiotensin II or plasma potassium, which are present in proportion to sodium deficiencies.

Enzymes synthesize aldosterone from cholesterol in the zona glomerulosa of the adrenal cortex.

Aldosterone and the kidney

Control of aldosterone release

• The role of baroreceptors
• The role of the juxtaglomerular apparatus
• The role of sympathetic nerves
• The role of the renin-angiotensin system

References

1. Williams JS, Williams GH. 50th anniversary of aldosterone. J Clin Endocrinol Metab. 2003 Jun;88(6):2364-72. Full text. PMID 12788829.