Figure 6.

Reciprocal target gene activation by SXR/PXR and CAR in vivo. (A) Constitutive upregulation of hepatic CYP2B10 mRNA in the liver of Alb-VPSXR mice. Mouse liver total RNAs were subjected to Northern blot analysis and probed for CYP3A11. The membranes were subsequently stripped and reprobed with cDNA probes of the glyceraldehyde-3-phosphate dehydrogenase (GAPDH, as a loading control), CAR, and tyrosine aminotransferase (TAT). To show the CYP2B10 regulation in wild type animals, male mice were subjected to a single intraperitoneal injection of control solvent (lane 1), PB (lane 2), or 3MC (lane 3). (B) Induction of CYP2B10 expression by PXR-specific ligand PCN in wild type males. (C) CTZ and PB, but not DEX, efficaciously induce CYP3A11 in PXR null mice.