Induction of liver cytochrome P-450 in mice by warfarin. Comparison of warfarin-, phenobarbitone-, and cobalt-induced hepatic microsomal protein patterns by PAGE after partial purification on octyl-sepharose CL-4B.

A rapid method is presented to separate mouse liver cytochrome P-450 from other components of the microsomal monooxygenase system and to increase specific activity by hydrophobic interaction chromatography on Octyl-Sepharose CL-4B by a factor of between 3.8 and 5.3. In addition it is shown that varieties of cytochrome P-450 can be separated from each other by Octyl-Sepharose CL-4B. After oral applications of 120 mg/kg warfarin once daily for three days SDS-PAGE analysis of the partially purified cytochrome P-450 fraction revealed a protein pattern in the 50 Kd region that is practically indistinguishable from that after conventional phenobarbitone pretreatment. On the other hand, cobalt pretreatment results in a different pattern that is distinguished from that of normals as well as from that of phenobarbitone- and warfarin-pretreated mice. From these results in conjunction with the previous finding of increased drug metabolic activity after warfarin pretreatment it is concluded that warfarin elicits phenobarbitone-like induction of the hepatic monooxygenases in mice.