Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
2005-11-24
pubmed:abstractText
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.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Acetaminophen, http://linkedlifedata.com/resource/pubmed/chemical/Benzoquinones, http://linkedlifedata.com/resource/pubmed/chemical/CYP3A protein, mouse, http://linkedlifedata.com/resource/pubmed/chemical/Caffeine, http://linkedlifedata.com/resource/pubmed/chemical/Cytochrome P-450 CYP1A2, http://linkedlifedata.com/resource/pubmed/chemical/Cytochrome P-450 CYP2E1, http://linkedlifedata.com/resource/pubmed/chemical/Cytochrome P-450 Enzyme System, http://linkedlifedata.com/resource/pubmed/chemical/Glutathione, http://linkedlifedata.com/resource/pubmed/chemical/Imines, http://linkedlifedata.com/resource/pubmed/chemical/N-acetyl-4-benzoquinoneimine, http://linkedlifedata.com/resource/pubmed/chemical/P-Glycoprotein, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Cytoplasmic and Nuclear, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Steroid, http://linkedlifedata.com/resource/pubmed/chemical/pregnane X receptor
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0090-9556
pubmed:author
pubmed:issnType
Print
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1827-36
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:16141365-Acetaminophen, pubmed-meshheading:16141365-Animals, pubmed-meshheading:16141365-Benzoquinones, pubmed-meshheading:16141365-Biological Transport, pubmed-meshheading:16141365-Caffeine, pubmed-meshheading:16141365-Cytochrome P-450 CYP1A2, pubmed-meshheading:16141365-Cytochrome P-450 CYP2E1, pubmed-meshheading:16141365-Cytochrome P-450 Enzyme System, pubmed-meshheading:16141365-Glutathione, pubmed-meshheading:16141365-Hepatocytes, pubmed-meshheading:16141365-Imines, pubmed-meshheading:16141365-Intestinal Absorption, pubmed-meshheading:16141365-Liver, pubmed-meshheading:16141365-Mice, pubmed-meshheading:16141365-Mice, Inbred C57BL, pubmed-meshheading:16141365-P-Glycoprotein, pubmed-meshheading:16141365-Receptors, Cytoplasmic and Nuclear, pubmed-meshheading:16141365-Receptors, Steroid, pubmed-meshheading:16141365-Transcription, Genetic
pubmed:year
2005
pubmed:articleTitle
Role of the nuclear receptor pregnane X receptor in acetaminophen hepatotoxicity.
pubmed:affiliation
Department of Pharmacology and Toxicology, Dartmouth Medical School, Hanover, New Hampshire, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural