Suppression of Plasma Renin Activity in Primary Aldosteronism

THE OCCURRENCE in a hypertensive patient of increased production of aldosterone, and of the hypokalemia which often accompanies it, is due either to (1) the presence of an aldosterone-secreting adrenocortical tumor (primary aldosteronism), or (2) the presence of a functional renal hemodynamic change which stimulates the renal juxtaglomerular cells to secrete into the blood abnormally large amounts of renin. In the latter case, an increased quantity of angiotensin II is thus generated. Angiotensin II has been established to be a potent stimulus for the secretion of aldosterone by the adrenal cortices of man.1,2Although increased secretion of aldosterone can be induced in man by other mechanisms, it is now clear that, when hypersecretion of aldosterone occurs in human renal hypertension (secondary aldosteronism), it is the result of increased activity of the renin-angiotensin system. This seems to be true whether the decreased "stretch"3at the renal baroreceptor site (the