C20 steroids. The metabolism of 3-hydroxy-19-nor[21-14C]pregna-1,3,5(10)-trien-20-one in the rabbit.
1. The metabolism of 3-hydroxy-19-norpregna-1,3,5(10)-trien-20-one, a possible product of the aromatization of progesterone or pregnenolone, has been studied. 2. After oral administration of this C(20) steroid as the 21-(14)C-labelled compound to two groups of rabbits, the excretion pattern of metabolites in the urine was examined. 3. At 14 days after administration, 3.3-6.5% of the radioactivity had appeared in the urine, 71-79% in the faeces and approx. 10% remained in the gut. 4. A metabolite, isolated from urine mainly as the unconjugated steroid, was identified as 19-norpregna-1,3,5(10)-triene-3,20alpha-diol and constituted 18.5-22% of the total urinary radioactivity. 5. A minor component of the urinary unconjugated steroids was identified as 19-norpregna-1,3,5(10)-triene-3,17alpha,20alpha-triol. 6. A further 2-7.5% of the total urinary radioactivity, isolated only from the urinary sulphate fraction, was tentatively identified as an 18-oxygenated derivative of the administered steroid.
D000818:Animals; D002247:Carbon Isotopes; D002845:Chromatography; D002854:Chromatography, Paper; D005243:Feces; D005260:Female; D005965:Glucuronates / Q000652:urine; D007422:Intestines / Q000032:analysis; D008832:Microchemistry; D011278:Pregnanes / Q000378:metabolism*; D011817:Rabbits; D013256:Steroids / Q000138:chemical synthesis / Q000378:metabolism* / Q000652:urine; D013431:Sulfates / Q000652:urine
D002247:Carbon Isotopes; D005965:Glucuronates; D011278:Pregnanes; D013256:Steroids; D013431:Sulfates