Effect of MC treatment on hepatic POR mRNA (A), protein (B), and catalytic activity (C) in wild-type and LCN mice. (B) Immunoblot of microsomal protein (3 µg) using polyclonal antibody against rat POR, showing results for two vehicle (V)- and MC (M)-treated mice per genotype. Quantitative analysis of POR mRNA levels, relative to β-actin (A) and cytochrome c reduction activity (C). Data represent the mean ± S.D. of determinations from four mice per group, expressed as a percentage of the mean for the vehicle-treated wild-type mice. Mean cytochrome c reduction activity for the vehicle-treated wild-type mice was 176 ± 25 nmol/min/mg protein. The P values for the two-way ANOVA main effects were P = 0.0753 (treatment), P < 0.0001 (genotype), and P = 0.0802 (interaction) for POR mRNA, and P = 0.0172 (treatment), P < 0.0001 (genotype), and P = 0.0172 (interaction) for POR activity. Post-test outcomes were as follows: *significantly different (P < 0.05) from genotype-matched vehicle-control mice; †significantly different (P < 0.05) from treatment-matched wild-type mice.