Figure 4.

Role of AhR in PCB 126-induction of cytochrome P450 genes. Cells were treated with 10μM PCB 126 in the presence or absence of 1 x 10⁻⁶ M of the AhR antagonist, α-NF. The levels of CYP1A1 (A) and CYP1B1 (B) mRNAs were measured by real-time PCR. PCB 126 significantly increased CYP1A1 (A) and CYP1B1 (B) mRNAs and α-NF abrogated these effects. Error bars represent mean ± SE CYP1A1/β-actin (A) or CYP1B1/β-actin (B) mRNAs and are expressed as fold induction over vehicle alone (DMSO).

^ap < 0.01, significantly different from control group using the Bonferroni t-test after one-way ANOVA. ^bp < 0.01, ^cp < 0.05, significantly different from PCB 126 –treated group using the Bonferroni t-test after one-way ANOVA.