Abnormalities of renal function and circulatory reflexes in primary aldosteronism

The renal response to intravenous administration of isotonic saline solution and circulatory reflex reactivity was studied in nine patients with primary aldosteronism before and after surgical removal of an adrenal adenoma. In preoperative tests, infusion of saline was followed by abnormally rapid renal excretion of sodium and water, such as occurs in patients with autonomic insufficiency. Circulatory reflex function was also abnormal in all patients; the most severe impairment was shown by two patients with hypokalemia and weakness of long duration. Postoperatively, both renal and circulatory reflex responses returned to normal or near normal. In preoperative tests on three patients, potassium repletion effected a similar correction of both renal and circulatory reflex abnormalities. The cause of these abnormalities in patients with primary aldosteronism is not known. Potassium depletion may be a factor, although a general disturbance of autonomic cardiovascular function cannot be excluded.