SOLVOLYZABLE 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 showed that the method 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 sulfate and subjecting it to solvolysis, more than 90% of the tritiated DOC was recovered, after chromatography of the free DOC extract. This suggests that much of the solvolyzable DOC in human urine is present in the form of the sulfate conjugate. The levels of DOC, excreted as the solvolyzable conjugate in a variety of urine specimens, were much higher than those of free DOC, the former being 4.8-127 times higher than the amount of the latter. This highly variable ratio suggests that the site of production of solvolyzable DOC is different from that for free DOC. The only correlation between free and solvolyzable DOC was shown in dexamethasone-suppressed patients, in whom the mean percentage remaining after suppression was 30.6% for free DOC, 24.1% for solvolyzable DOC and 22.2% for cortisol. As solvolyzable 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; urine specimens left at room temperature for 1 wk could show rises of as much as 400% of their starting free DOC levels.