Journal article
Role of the nuclear receptor pregnane X receptor in acetaminophen hepatotoxicity
Drug metabolism and disposition, Vol.33(12), pp.1827-1836
12/2005
Handle:
https://hdl.handle.net/2376/117834
PMID: 16141365
Abstract
The pregnane X receptor (PXR) is a transcriptional regulator of xenobiotic metabolizing enzymes, including cytochrome P450 3A (CYP3A), and transporters. Pretreatment of mice and rats with inducers of CYP3A increases acetaminophen (APAP) hepatotoxicity. In untreated mice, the amount of hepatic CYP3A11 mRNA is 4-fold greater in PXR(-/-) mice compared to wild-type mice (Guo et al., 2003), a finding anticipated to increase APAP hepatotoxicity in PXR(-/-) mice. We investigated APAP hepatotoxicity in wild-type and PXR(-/-) mice in a C57BL/6 background, with APAP administered by gavage. Despite a 2.5-fold higher level of total hepatic CYP3A protein and a 3.6-fold higher level of CYP3A activity compared to wild-type mice, PXR(-/-) mice were less sensitive to APAP hepatotoxicity. Hepatic levels of CYP2E1 were identical in the two mouse lines, but hepatic CYP1A2 levels were 3-fold greater in wild-type mice compared to PXR(-/-) mice. Caffeine, an inhibitor of CYP1A2 activity and an enhancer of CYP3A activity, decreased APAP hepatotoxicity in wild-type mice. APAP uptake was 1.5-fold greater in wild-type mice compared to PXR(-/-) mice. No significant differences in the formation of APAP glucuronide and sulfate-conjugated metabolites were observed between wild-type and PXR(-/-) mice. Glutathione levels were similar in the two mouse lines and were transiently decreased to similar amounts after APAP administration. Our finding that APAP hepatotoxicity was decreased in PXR(-/-) mice indicates that PXR is an important modulator of APAP hepatotoxicity, through positive modulation of constitutive CYP1A2 expression and possibly through increased APAP absorption.
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Details
- Title
- Role of the nuclear receptor pregnane X receptor in acetaminophen hepatotoxicity
- Creators
- Kristina K Wolf - Department of Pharmacology and Toxicology, Dartmouth Medical School, Hanover, New Hampshire, USASheryl G WoodJane A HuntBrooke W Walton-StrongKazuto YasudaLubin LanSu X DuanQin HaoSteven A WrightonElizabeth H JefferyRonald M EvansJuliana G SzakacsLisa L von MoltkeDavid J GreenblattMichael H CourtErin G SchuetzPeter R SinclairJacqueline F Sinclair
- Publication Details
- Drug metabolism and disposition, Vol.33(12), pp.1827-1836
- Academic Unit
- Veterinary Clinical Sciences, Department of
- Publisher
- United States
- Grant note
- GM60346 / NIGMS NIH HHS AA12898 / NIAAA NIH HHS P30 CA21765 / NCI NIH HHS
- Identifiers
- 99900548370501842
- Language
- English
- Resource Type
- Journal article