Aldosterone response to ACTH stimulation in anephric and non-nephrectomized patients on regular hemodialysis

The effect of ACTH on plasma aldosterone concentration (PAC) and plasma cortisol concentration (PCC) has been investigated in 5 anephric and 6 non-nephrectomized patients on regular homodialysis. Basal PAC was significantly lower (p less than 0.01) in the anephric (mean 37.6 pg/ml) than in the nonnephrectomized group (mean 117.5 pg/ml), whereas basal PCC (18.6 and 16.5 mug/100 ml, respectively) did not differ significantly (p less than 0.05). Following administration of synthetic beta1-24 ACTH, the maximal percentage increase in PAC was significantly lower ( less than 0.001) in the anephric (105%) than in the nonnephrectomized group (286%). The rise in PCC, 118%, in both groups showed no significant difference (p less than 0.05). The higher basal level of PAC and the more pronounced response to ACTH in nonnephrectomized patients correlated with higher basal levels of plasma renin activity compared with the anephric group. An influence of the remaining renin-angiotensin system on the ability to react to an ACTH stimulation is therefore suggested.