Deoxycorticosterone and aldosterone clearance and binding in normal and hypertensive man

Deoxycorticosterone (DOC) may play a role in several hypertensive disorders in man, but the dynamics of DOC metabolism are unclear. To characterize DOC binding to plasma proteins and its MCR, 12 patients with essential hypertension and 10 age-matched controls were studied. In control subjects, the DOC MCR was nearly identical to the stimultaneously measured aldosterone MCR (719 +/- 32 vs. 734 +/- 61 liters/m2 x day, respectively), and the MCRs of both steroids were not significantly different in essential hypertension (682 +/- 49 and 672 +/- 50 liters/m2 x day, respectively). Whole blood MCR was also unaltered by hypertension. The DOC whole blood MCRs were 1056 +/- 85 and 1040 +/- 69 liters/m2 x day for control and hypertensive subjects, respectively. The aldosterone whole blood MCRs were 916 +/- 96 and 941 +/- 67 liters/m2 x min. The similarity of the DOC MCR to the aldosterone MCR suggested minimal binding of DOC to high affinity carrier proteins, and this was confirmed by equilibrium dialysis with [3H]DOC at 37 C. In plasma, 6 +/- 1% of DOC is unbound, 84 +/- 3% is bound to albumin, and only 10 +/- 4% is bound to nonalbumin proteins. We conclude that the dynamics of DOC closely resemble those of aldosterone, with minimal plasma binding to specific binding proteins and high MCR that are unaltered in essential hypertension.