Increased atrial natriuretic peptide in the nephrotic syndrome. Relationship to the renal function and the renin-angiotensin-aldosterone system

Abstract

Atrial natriuretic peptide (ANP), angiotensin II (Ang II), and aldosterone (Aldo) in plasma and creatinine clearance (C_cr) were determined during basal conditions in 17 patients with the nephrotic syndrome and 20 control subjects. In addition, six of the patients were studied after seven remissions of the syndrome. In the nephrotic syndrome ANP was higher than in the control group (9.7 (median) versus 7.2 pmol/l, p<0.01), C_cr was lower (55 versus 99 ml/min, p<0.01). Angiotensin II and Aldo were the same in patients and control subjects. After remission of the syndrome ANP was reduced (11.2 to 5.4 pmol/l, n=7, p<0.02) and C_cr increased (52 to 84 ml/min, n=7, p<0.02), whereas Ang II and Aldo were unchanged. A significant, negative correlation was found between ANP and C_cr in the subgroup of patients in whom the syndrome remitted (p=-0.547, n=14, p<0.05). Atrial natriuretic peptide was not correlated to either Ang II or Aldo in either of the groups. It is concluded that patients with the nephrotic syndrome have elevated ANP, and it is suggested that a high ANP may be a compensatory phenomenon induced by a decreased renal ability to eliminate sodium and water.

Key Words:

• aldosterone
• angiotensin II
• atrial natriuretic peptide
• kidney function
• nephrotic syndrome