Corticosteroid metabolism in isolated rat kidney in vitro. II. Sex dependency of metabolism and formation of 11-dehydro-corticosterone.

We have previously demonstrated that isolated kidneys from male rats convert corticosterone (B). The metabolites are formed in renal tissue, released into the recirculating perfusate and excreted in the urine (5). They have been identified as: 11-dehydro-20 zeta-dihydro-B (met I), 20 zeta-dihydro-B (met II) and 5 alpha-H-4,5-dihydro-B (met III), using HPLC. In view of sex dependency of hepatic corticosteroid metabolism we have presently investigated whether or not equivalent sexual differences exist in renal tissue. In applying appropriate HPLC-techniques we could demonstrate a fourth metabolite formed from B, which was chromatographically identical with 11-dehydro-B (= met IV). Female rat kidneys form predominantly the less polar metabolites III and IV, in contrast to kidneys from male rats, which produce met III and the more polar metabolites I and II.