NADPH-cytochrome P-450 reductase is not a component of the liver microsomal steroid 5-alpha reductase |
| |
Authors: | K C Cheng R W Wang A Y Lu |
| |
Affiliation: | Dept. Pediatrics, Cornell University Medical College, NY, NY 10021. |
| |
Abstract: | Liver microsomal steroid 5-alpha-reduction is catalyzed by a NADPH-dependent enzyme system. The requirement of NADPH-cytochrome P-450 reductase to shuttle reduction equivalents from NADPH to steroid 5-alpha-reductase was investigated using an inhibitory antibody against NADPH-cytochrome P-450 reductase. This antibody preparation inhibited cytochrome c reduction in microsomes from female rat liver with an I50 of 0.75 mg antibody/mg of microsomal protein. Benzphetamine N-demethylation and testosterone 6-beta-hydroxylation, two cytochrome P-450-mediated oxidative reactions, were inhibited by the antibody. On the other hand, testosterone 5-alpha-reductase was not affected by the antibody. These results suggest that NADPH-cytochrome P-450 reductase is not an obligatory component of the liver microsomal steroid 5-alpha-reduction. |
| |
Keywords: | |
|
|