Metabolism of radiolabeled corticosterone in an adult with the 17 alpha-hydroxylase deficiency syndrome.

[4-14C]Corticosterone was administered to a woman with the 17 alpha-hydroxylase deficiency syndrome and urine was collected for 72 h. Sixty-three percent of the radioactivity was eliminated on the first day, 10.3% on the second, and 3.8% on the third, making a total recovery of 77%. On the first day, 85% of the recovered radioactivity was in the glucuronide conjugates of corticosterone, 10.6% was in the sulfate form of this steroid, and 3.9% was in the free forms of the steroid. On the following 2 days, the proportion of labeled glucuronides and free steroids decreased and that of labeled sulfates increased. On the first day of collection, the major radiolabeled metabolites were 21-hydroxylated steroids (e.g. allo-tetrahydrocorticosterone and 5 alpha- and beta-pregnane-3 alpha,11 beta,20 alpha,21-tetrol), but by the third day, at least 75% of the excreted activity was associated with 21-deoxysteroids, such as 3 alpha,20 alpha-dihydroxy-5 alpha (and beta)-pregnan-11-one and 5 alpha- and beta-pregnane-3 alpha,11 beta,20 alpha-triol. Bacterial metabolism in the intestinal tract is responsible for the dehydroxylation. 6 alpha-Hydroxytetrahydrocorticosterone was tentatively identified among several new metabolites of corticosterone.