Effect of hepatic microsomal mixed-function oxidase activities in rats pretreated with Nocardia rubra cell wall...

Hepatic microsomal mixed-function oxidase activities such as aniline hydroxylase and aminopyrine demethylase activities decreased to about 50% of the control levels 1 day after i.v. injection of 4.0 mg/kg Nocardia rubra cell wall skeleton (N-CWS) to rats. These levels recovered gradually, and returned to almost the same levels as the control 6 days after injection. Cytochrome P-450 content and NADPH-cytochrome c reductase activity showed almost the same temporal changes as the mixed-function oxidase activities; cytochrome b5 content ws less affected than the others by the treatment. The enzyme activities and contents decreased less 1 and 3 days after i.v. injection of 0.4 and 0.04 mg/kg N-CWS than after the 4.0 mg/kg injection. These levels recovered gradually as well as the 4.0 mg/kg group. Three days after i.p., s.c. and p.o administration of 4.0 mg/kg N-CWS to rats, aniline hydroxylase activity and cytochrome b5 content decreased significantly to 82 and 92% of the control, respectively, in the s.c. pretreated group, but the others did not change significantly.