Influence of Acute Stimuli on Plasma Aldosterone Concentration in Anephric Man and Kidney Allograft Recipients

The response of plasma aldosterone concentration to postural variation, adrenocorticotropic hormone (ACTH), and angiotensin II was studied in five kidney allograft recipients and compared with the response observed in the same five subjects during the anephric period. Normal subjects acted as intact controls. After 2 hours of normal ambulation, plasma aldosterone levels increased in normal subjects (6.7 ± 1.6 to 22.9 ± 2.7 ng/100 ml plasma), remained unchanged in anephric patients (4.5 ± 1.0 to 5.2 ± 1.1 ng/100 ml plasma), and increased in kidney allograft recipients (6.8 ± 1.5. to 25.6 ± 1.9 ng/100 ml plasma). After ACTH administration, plasma aldosterone levels increased in normal subjects (7.5 ± 1.8 to 24.3 ± 2.5 ng/100 ml plasma), anephric subjects studied immediately after hemodialysis (16.6 ± 1.6 to 30.0 ± 2.6 ng/100 ml plasma), and kidney allograft recipients (5.0 ± 1.6 to 22.3 ± 1.4 ng/100 ml plasma). After angiotensin II infusion, plasma aldosterone levels increased in normal subjects (7.2 ± 1.8 to 42.5 ± 3.6 ng/100 ml plasma), remained unchanged in anephric subjects (8.6 ± 2.1 to 7.4 ± 1.6 ng/100 ml plasma), and increased in kidney allograft recipients (6.3 ± 1.5 to 40.2 ± 3.1 ng/100 ml plasma). In anephric man after prolonged absence of the renal renin-angiotensin system ACTH increased the rate of aldosterone secretion but angiotensin II had little effect. An intact renal renin-angiotensin system was necessary for increased aldosterone secretion in response to postural variation.