Solvolysable deoxycorticosterone conjugates in human urine.

The nature of the urinary conjugate converted by solvolysis, to free unconjugated deoxycorticosterone (DOC) was studied. A comparison of 11 solvolysis techniques has shown that the method employed in this study yielded 86% of the highest yield by any of the techniques tried. Three successive chromatographic systems on paper showed that no appreciable amounts of contaminants were present in the free DOC eluates, following solvolysis. By preparing authentic [3H]DOC sulphate and subjecting it to solvolysis it was shown that more than 90% of the tritiated DOC was recovered, after chromatography of the free DOC extract. This suggests that much of the solvolysable DOC in human urine is present in the form of the sulphate conjugate. The levels of DOC, excreted as the solvolysable conjugate in a variety of urine specimens, were shown to be much higher than those of free DOC, the former being 4-8 to 127 times higher than the amount of the latter. This highly variable ratio suggests that the site of production of solvolysable DOC is different from that for free DOC. The only correlation between free and solvolysable DOC was shown in dexamethasone-suppressed patients, in whom the mean percentage remaining after suppression was 30-6% for free DOC, 24-1% for solvolysable DOC and 22-2% for cortisol. As solvolysable DOC is present in much larger amounts in urine, care is necessary in the storage of urine samples in which free DOC estimates are to be made, as we found that urine specimens left at room temperature for 1 week could show rises of as much as 400% of their starting free DOC levels.

Deoxycorticosterone excretion in normal, hypertensive and hypokalaemic subjects.

1. Radioimmunoassay has been used to detect and estimate the urinary excretion of deoxycorticosterone (DOC) in normal, hypertensive and hypokalaemic subjects. The range of excretions in ten healthy normal subjects was 41-232 pmol (13.7-76.7 ng) daily, with a mean of 124 pmol (41 ng). 2. In fourteen subjects with essential hypertension without metabolic disturbance the range found was 29-144 pmol (9.7-47.7 ng) daily, with a mean of 87 pmol (28.8 ng), which is not significantly different from that in normal subjects. 3. In twelve patients with Cushing's syndrome due to adrenal cortical hyperplasia the range found was 26-542 pmol (8.7-179 ng). Ten of these twelve patients had values within normal limits. 4. Of nine subjects showing hypokalaemia, eight had elevated excretion of deoxycorticosterone with values from 263 to 5515 pmol (87-1820 ng) daily. Seven of these were hypertensive and two were normotensive. The elevated excretion of deoxycorticosterone found in hypokalaemic subjects is thus not confined to those with hypertension. 5. No correlation has been found between excretion rates for aldosterone and deoxycorticosterone. Raised excretion of the latter provides an indicator of disturbed adrenal cortical metabolism.

Simplification of urinary aldosterone measurement by radioimmunoassay.

An anti-aldosterone serum has been used to measure urinary aldosterone concentration. A single stage of paper chromatography provides an extract of sufficient purity. Further purification by additional chromatography in a different solvent system only improves the purity by 3% +/- 8 (SD). Blanks are negligible and recovery of added aldosterone is 104% +/- 10 (SD).A simplified rapid screening assay capable of revealing gross deviations from the normal is also suggested. The diagnostic value of the assay is indicated.