Aldosterone is a steroid hormone secreted by the adrenal cortex and is the principle mineralocorticoid controlling sodium and potassium balance.[1],[2] Its primary role is to promote unidirectional salt reabsorption in epithelial tissues. Aldosterone is synthesized from cholesterol in the zona glomerulosa of the adrenal cortex and its secretion is regulated via the renin-angiotensin system.[3]

Reference:
[1]. Agarwal, M.K., and Mirshahi, M. General overview of mineralocorticoid hormone action. Pharmacology & Toxicology 84, 273-326 (1999).
[2]. Rogerson, F.M., and Fuller, P.J. Mineralocorticoid action. Steroids 65, 61-73 (2000).
[3]. Lumbers, E.R. Angiotensin and aldosterone. Regulatory Peptides 80, 91-100 (1999).