Effect of Hemodialysis on the Metabolic Clearance Rate, Plasma Concentration and Blood Production Rate of Aldosterone in Anephric Man

Abstract

Plasma aldosterone concentration (PAC) has been found to increase in anephric patients in response to hemodialysis. To determine whether this increase in PAC resulted from an increase in aldosterone production rate (APR) or a decrease in metabolic clearance rate of aldosterone (MCR), sequential determinations of PAC and MCR were made in 5 anephric patients immediately before and 6 hr after the start of dialysis. In 4 patients, PAC increased from 10.8 ± 1.3 (mean ± SE) to 15.5 ± 0.7 ng/100 ml plasma in response to dialysis. Mean MCR was 1615 ± 40 I/day before dialysis and 1682 ± 40 I/day during dialysis and the calculated APR increased from 173.3 ± 18.9 μg/day prior to dialysis to 262.3 ± 16.8 μg/day during dialysis. The fifth patient arrived with a high PAC (22.9 ng/100 ml) and his PAC decreased during dialysis (8.8 ng/100 ml). The decrease in PAC correlated well with loss of plasma K from 7.4 mEq/1 to 3.6 mEq/1 during dialysis. MCR also fell from 2345 l/day to 2024 l/day. These data suggest that a change in the APR rather than a change in MCR is the major factor regulating plasma aldosterone concentration in anephric individuals during hemodialysis.