figure1

Figure 1.Renin-angiotensin-aldosterone and potassium-aldosterone negative-feedback loops. Aldosterone production is determined by input from each loop. (Adapted and redrawn from Williams GH, Dluhy RG. Disease of the adrenal cortex. In: Fauci AD, Braunwald E, Isselbacher KJ, et al, eds. Harrison’s Principles of Internal Medicine. 15th ed. New York: McGraw-Hill, 2001)