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 Enzyme | Redox System | OT Conversion | Control Reaction |
|---|---|---|---|
| CYP11A1 | Mitochondrial | + | Cholesterol → pregnenolone |
| CYP11B1 | Mitochondrial | + | DOC → corticosterone |
| CYP11B2 | Mitochondrial | + | DOC → corticosterone |
| CYP17A1 | Microsomal | − | Progesterone → 17-hydroxyprogesterone |
| Microsomal plus cytochrome b5 | − | 17-hydroxyprogesterone → androstenedione | |
| CYP19 | Microsomal | − | Androstenedione → estrone |
| CYP21A2 | Microsomal | − | Progesterone → 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.