Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2002-5-15
pubmed:abstractText
Microsomal enzyme inducers are capable of modulating biliary excretion of organic anions and bile flow, but the mechanism for modulation is unknown. Therefore, this study was designed (1) to determine the effects of microsomal enzyme inducers on protein and mRNA expression of rat multidrug resistance protein 2 (Mrp2), a canalicular organic anion transporter; and (2) to determine whether classes of microsomal enzyme inducers affect Mrp2 expression in similar manners, thus implying specific nuclear receptor-activated transcription pathways. Male Sprague-Dawley rats were treated with aryl hydrocarbon (Ah) receptor (AhR) ligands/cytochrome P450 (CYP) 1A inducers, constitutive androstane receptor (CAR) ligands/CYP2B inducers, pregnane-X receptor (PXR) ligands/CYP3A inducers, peroxisomal proliferator-activating receptor-alpha (PPARalpha) ligands/CYP4A inducers, antioxidant/electrophile response element (ARE/EpRE) ligands, CYP2E1 inducers, or control vehicle. Mrp2 protein levels were significantly increased by all 3 PXR ligands/CYP3A inducers (pregnenolone-16alpha-carbonitrile [PCN], spironolactone [SP], and dexamethasone [DEX]) and by both ARE/EpRE ligands (ethoxyquin [EQ] and oltipraz [OPZ]). In contrast, PPARalpha ligands/CYP4A inducers (clofibric acid [CLOF], di-(2-ethylhexyl)phthalate [DEHP], and perfluorodecanoic acid [PFDA]) tended to decrease Mrp2 protein levels. Mrp2 mRNA expression was not significantly affected by any microsomal enzyme inducer, though ARE/EpRE ligands tended to upregulate Mrp2 mRNA. In summary, this study demonstrates that Mrp2 protein levels are significantly increased by PXR ligands/CYP3A inducers and ARE/EpRE ligands, and appear to be decreased by PPARalpha ligands/CYP4A inducers by posttranscriptional mechanisms. Furthermore, these data suggest that measuring Mrp2 mRNA is not a good indicator for Mrp2 protein expression in vivo.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1096-6080
pubmed:author
pubmed:issnType
Print
pubmed:volume
67
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
182-9
pubmed:dateRevised
2010-9-17
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Regulation of rat multidrug resistance protein 2 by classes of prototypical microsomal enzyme inducers that activate distinct transcription pathways.
pubmed:affiliation
Environmental Health and Occupational Medicine Center, Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160-7417, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.