The recognition of a soluble cytochrome P450 in rat liver

The presence of hepatic soluble cytochrome P450 was investigated in the rats that were pretreated with CCl4, CS2 and DENA + PCBs. The dithionite-reduced CO difference spectrum of the hepatic 204000 x g supernatant of these rats showed its maximum at 455 nm. Aniline and hexobarbital could react with the hepatic 204000 x g supernatant to give the substrate binding spectra of P450; differences were observed between the substrate-induced difference spectra of the 204000 x g supernatant and that of the microsomal fraction. These results indicate the existence of a hepatic soluble P450.