Adrenalectomy causes a delayed increase of inactive plasma renin in rats.

Using a new assay for inactive renin in rat plasma, inactive renin was unchanged 24 h after bilateral adrenalectomy but increased about threefold, from 0.43 Goldblatt units (GU)/l (range 0.27-0.62 GU/l; n = 14) to 1.24 GU/l (0.74-1.94 GU/l; n = 14) after 48 h. The increase was abolished by substitution with the mineralocorticoid deoxycorticosterone acetate. The results are in accordance with the high plasma concentration of inactive renin, previously reported in humans with adrenal insufficiency, and do not support activation of inactive renin in the circulation.