STOFFWECHSEL VON 16-OXO-ÖSTRON BEIM MENSCHEN

ABSTRACT To each of two male subjects, 10 mg of 16-oxo-oestrone was administered intramuscularly. By various microchemical reactions, the following phenolic steroids were identified in urine: oestriol, 16-epi-oestriol, 16-oxo-17β-oestradiol, 16α-hydroxyoestrone, 16β-hydroxyoestrone, 17-epi-oestriol and 16,17-epi-oestriol. Calculated on the basis of the administered amount of 16-oxo-oestrone, the average total excretion during the 5 days of the experiment was 12% for oestriol, 3.9% for 16-epi-oestriol, 2.9% for 16-oxo-17β-oestradiol, 1.5% for 16α-hydroxyoestrone, 0.7% for 16β-hydroxyoestrone, 0.6% for 17-epi-oestriol and 0.3% for 16,17-epi-oestriol. These results confirm previous experiments with human liver slices and show that, in addition to 17β-, 16α- and 16β-hydroxysteroid oxidoreductases, a 17α-hydroxysteroid oxidoreductase is present in man which reacts with phenolic steroids. The total recoveries of all reduction products of 16-oxo-oestrone were 26% for subject A and 18% for subject B. These relatively low values suggest that 16-oxo-oestrone is subjected in man not only to a reduction but also to an oxidative metabolism which may be of quantitative significance.