Atrial natriuretic factor, angiotensin II, aldosterone, arginine vasopressin and urinary prostaglandin E2excretion in hyperfiltrating unilaterally nephrectomized humans

Abstract

To investigate the degree to which long-term adaptive changes in the remaining kidney after unilateral nephrectomy are dependent on hormonal factors, we measured resting plasma levels of atrial natriuretic factor (ANF), angiotensin II (Ang II), aldosterone (Aldo), arginine vasopressin (AVP), urinary excretion of prostaglandin E2 (UPGE2), creatinine clearance, and fractional sodium excretion (FENa) in 11 unilaterally nephrectomized persons (UNP) 1-11 years after operation and in 13 control subjects (study 1). Additionally, to investigate whether the remnant kidney's ability to excrete an acute sodium load is dependent on hormonal changes, Ang II, Aldo, AVP, sodium excretion, UPGE2, and free-water reabsorption (TcH2O) were measured in response to acute intravenous sodium loading in nine UNP and 14 controls (study 2). Study 1 showed that UNP exhibited hyperfiltration compared with controls (creatinine clearance 79 ml/min/1.73 m2/kidney vs 53, p less than 0.01) and increased FENa (0.82% vs 0.58, p less than 0.01). Despite this, ANF, Ang II, Aldo, and AVP did not deviate significantly from controls. UPGE2 was increased in UNP compared with controls (108 ng/24 h/kidney vs 64, p less than 0.01). Study 2 showed that UNP exhibited a normal natriuretic response but an exaggerated increase in TcH2O (6.0 ml/min/kidney vs 3.9, p less than 0.02). However, the response in plasma levels of Ang II, Aldo and AVP was the same in UNP and in controls. We conclude that the long-term adaptation in the remaining kidney after unilateral nephrectomy does not involve any major changes in ANF, Ang II, Aldo, or AVP. The increase in PGE2 may be a compensatory phenomenon that tends to preserve renal function.