Metabolism of OT by human steroidogenic P450 enzymes

OT conversion was assayed in a reconstituted in vitro system with NADPH and the natural redox system (mitochondrial: AdR and Adx; microsomal: CPR) and was analyzed by HPLC.

P450 EnzymeRedox SystemOT ConversionControl Reaction
CYP11A1Mitochondrial+Cholesterol → pregnenolone
CYP11B1Mitochondrial+DOC → corticosterone
CYP11B2Mitochondrial+DOC → corticosterone
CYP17A1MicrosomalProgesterone → 17-hydroxyprogesterone
Microsomal plus cytochrome b517-hydroxyprogesterone → androstenedione
CYP19MicrosomalAndrostenedione → estrone
CYP21A2MicrosomalProgesterone → DOC
  • Product formation is indicated by a plus sign, and no product forming activity is indicated by a minus sign. A positive control was performed with a natural substrate.