Fig. 4.

Docetaxel induces mdr1a.fLUC expression via PXR. (A) pxr^+/+ (WT) and pxr^−/− (KO) mice that were heterozygous for the mdr1a.fLUC allele were given 10 mg/kg docetaxel (Doc) or polysorbate 80 (Veh) by i.p. injection at times 0, 72, and 144 hours after the initial injection as indicated by dashed arrows. Results are from a single experiment, with expression quantified as in previous figures. (B–D) Normalized luminescence intensities at the 8-hour time points after each dosing cycle. Data from all mice from one single-dosing experiment with the KO mice (included in dose 1 only) and one multidosing experiment with WT and KO mice (included in doses 1–3) are pooled and averaged (± S.E.M.). Panels show comparisons as in Fig. 1. WT + Doc (n = 9 for all doses), KO + Doc (n = 21 for dose 1, n = 9 for doses 2 and 3), WT + Veh (n = 8 for all doses), KO + Veh (n = 21 for dose 1, n = 9 for doses 2 and 3). *P ≤ 0.05; **P ≤ 0.01; ***P ≤ 0.001; ****P ≤ 0.0001.