Dimethylnitrosamine demethylation by reconstituted liver microsomal cytochrome P-450 enzyme system.

ABSTRACT: Oxidative demethylation of dimethylnitosamine was studied with both reconstituted and unresolved liver microsomal cytochrome P-450 enzyme systems from rats and hamsters. Proteinase treatment of liver microsomal preparations yielded cytochrome P-450 particulate fractions. Both cytochrome P-450 and NADPH- cytochrome c reductase fractions were required for optimum demethylation activity. Particulate cytochrome P-450 fractions were more effecient than either Triton X-100- or cholatesolubilized preparations of these particles in demethylation activity with rat and hamster liver preparations appear to be due to differences in specificity in their cytochrome P-450 fractions.

SUBMITTER: Lotlikar PD 

PROVIDER: S-EPMC1172528 | biostudies-other | 1975 Dec

REPOSITORIES: biostudies-other