Fig. 4.

The effects of 8-MOP on NNK bioactivation in lung and liver microsomes from Cyp2a5-null mice. The rates of formation of OPB and HPB were determined for lung (top) and liver (bottom) microsomal samples that had been preincubated with 0, 0.5, or 2.5 μM 8-MOP, as described under Materials and Methods, with NNK at 5 μM. Values represent means ± S.D. of data from three separate microsomal samples, each prepared from pooled tissues from five 2-month-old female Cyp2a5-null mice. **, p < 0.01, compared with the 0-μM 8-MOP group (one-way ANOVA followed by Tukey's post hoc test). The extents of inhibition (%) are indicated.