A mixture of [19-3H]hydroxyandrostenedione and [14C]androstenedione was administered intravenously to 3 women and urine was collected. Only negligible radioactivity could be extracted from the untreated urine. Most of the 14C but only 11% of the 3H was rendered solube in organic solvents by beta-glucuronidase. [3H-19]hydroxyandrostenedione was recovered from this fraction. The conjugates remaining in the urine were extracted into CHCl3 as their pyridinium salts. After solvolysis of the extract with HCLO4 in tetrahydrofuran, neutral metabolites were obtained. Substances extractable from water with organic solvents were obtained by solvolysis of the conjugates with perchloric acid in tetrahydrofuran. [3H-19]hydroxyandrostenedione was identified by isotopic dilution as the major product of solvolysis. Thus, 19-hydroxyandrostenedione undergoes conjugation with glucuronic acid and probably sulfuric acid, most likely at C-19. The major urinary metabolite is the sulfate-like conjugate. Reduction in ring A is less important than for other steroids.

Incubation of deoxycorticosterone (DOC) with human fecal flora results in the formation of a variety of products depending on the experimental conditions. Fecal flora, diluted 101 to 107, reduced DOC (16 μg/ml) to THDOC which was further metabolized to 3α-pregnanolone. Small amounts of 3α-pregnanolone, in turn, were transformed to pregnandione and 3β-pregnanolone. Another structure, tentatively identified as 20,21-dihydroxy-5-pregnan-3 one (metabolite X) was often formed in yields of 5–10% in the early phases of incubation. These findings were corroborated in experiments using purified THDOC and purified pregnanolone as substrates.

A mixture of 4-14C-delta4-androstene-3, 17-dione and 6,7-3 H-19-hydroxy-delta4-androstene-3, 17-dione was intravenously injected into three women, and the 3H/14C ratios in urinary 19-hydroxyandrostenedione and urinary estrogens were determined. The ratios of 3H/14C in the estrogens were similar to those of the dose, while the ratios in urinary 19-hydroxyandrostenedione were mcuh higher than those of the dose. The fractional conversions of androstenedione to estrone and of 19-hydroxyandrostenedione to estrone are therefore similar. However, little, if any, 19-hydroxyandrostenedione produced during aromatization enters the circulation and mixes with injected 19-hydroxyandrostenedione.