Linked Life Data

18794335

Source:http://linkedlifedata.com/resource/pubmed/id/18794335

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2009-1-1
pubmed:abstractText
CYP3A4 is an important xenobiotic metabolizing enzyme. We previously found that CYP2C55 is highly up-regulated in Cyp3a(-/-) mice. Here, we have further investigated the mechanism of regulation of CYP2C55 and other detoxifying systems in Cyp3a(-/-) mice. Induction studies with prototypical inducers demonstrated an important role for the nuclear receptors PXR and CAR in the up-regulation of CYP2C55. Subsequent diet-switch experiments revealed that food-derived xenobiotics are primarily responsible for the increased induction of CYP2C55, as well as of several other primary detoxifying systems in Cyp3a(-/-) mice. Our data suggest that CYP3A normally metabolizes food-derived activators of PXR and/or CAR, explaining the increased levels of such activators in Cyp3a(-/-) mice and subsequent up-regulation of a range of detoxifying systems. Interestingly, our studies with tissue-specific CYP3A4 transgenic Cyp3a(-/-) mice revealed that not only hepatic but also intestinal expression of CYP3A4 could reduce the hepatic expression of detoxifying systems to near wild-type levels. Apparently, intestinal CYP3A4 can limit the hepatic exposure to food-derived activators of nuclear receptors, thereby regulating the expression of a range of detoxifying systems in the liver. This broad biological effect further emphasizes the importance of intestinal CYP3A activity and could have profound implications for the prediction of drug exposure.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1530-6860
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
23
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
224-31
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Intestinal cytochrome P450 3A plays an important role in the regulation of detoxifying systems in the liver.
pubmed:affiliation
Division of Experimental Therapy, The Netherlands Cancer Institute, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't