Metabolism of 5 alpha-dihydroprogesterone in women and men: 3 beta- and 3 alpha-,6 alpha-dihydroxy-5 alpha-pregnan-20-ones are major urinary metabolites.

The metabolism of 5 alpha-dihydroprogesterone (5 alpha-DHP) in women and men was evaluated by defining the pattern and identity of selected metabolites excreted in urine after the iv infusion of radiolabeled 5 alpha-DHP. Virtually all of the radioactivity in urine (approximately 37% of the administered dose) was excreted within 72 h. Quantitatively, the 2 major urinary metabolites of 5 alpha-DHP in each of 13 studies conducted in 7 women and 2 men were 3 beta,6 alpha-dihydroxy-5 alpha-pregnan-20-one and 5 alpha-pregnane-3 alpha,20 alpha-diol, which could be extracted after beta-glucuronidase, but not solvolysis, treatment of the urine. Radiolabeled 3 alpha,6 alpha dihydroxy-5 alpha-pregnan-20-one (glucuronoside), in lesser amounts, also was identified in the urine of each subject. The 3 alpha/beta, 6 alpha-dihydroxy-5 alpha-pregnan-20-ones arise through specific extrahepatic pathways of progesterone/5 alpha-DHP metabolism. These metabolites are not the products of the enzyme reaction catalyzed by the cyto...