Urinary excretion of catecholamines in patients with primary aldosteronism before and after unilateral adrenalectomy

The authors compared urinary excretion of noradrenalin (NA), adrenalin (A) and dopamine (DA) in 12 patients with primary aldosteronism (PA), 54 healthy controls and 17 patients with fixed benign essential hypertension (BEH), and in PA investigated the changes occurring in the catecholamine spectrum after removal of aldosterone-producing adrenal adenoma. The patients with PA before adrenalectomy differed from the controls and patients with BEH by low NA excretion and high DA excretion. After unilateral adrenalectomy, patients with PA presented simultaneously with BP, aldosterone and renin normalization a rise in NA excretion and a drop in urinary DA to similar or lower values than those found in the controls and BEH. The results show that changes in urinary catecholamines excretion in A may be a secondary consequence of hypermineralocorticism. High DA may be the consequence of a mobilization of contra-regulatory natriuretic mechanisms in the course of aldosterone-induced sodium retention. Low NA and A may participate in lowering the plasma renin activity which in PA in suppressed, sometimes disproportionately to the actual body sodium content.