title: Impact of probe compound in MRP2 vesicular transport assays.
abstract: MRP2 is an efflux transporter that is expressed mainly in the canalicular membrane of hepatocytes, where it expels polar and ionic compounds into the bile. MRP2 is also present in the apical membrane of enterocytes and epithelial cells of proximal tubules of the kidney. Inhibition of MRP2 transport can lead to the accumulation of metabolites and other MRP2 substrates up to toxic levels in these cells. The transport properties of MRP2 are frequently studied with the vesicular transport assay. The assay identifies compounds that interact with MRP2 by measuring the effect of a compound on the transport of a radioactively labeled or fluorescent probe. We have compared the effect of eight selected test compounds (quercetin, disopyramide, paracetamol, indomethacin, diclofenac, estrone-3-sulfate, budesonide, and thioridazine) on the MRP2-mediated transport of three commonly used probes: 5(6)-carboxy-2,7-dichlorofluorescein, leukotriene C4 and estradiol-17-β-d-glucuronide (E217βG). Five of the test compounds had different probe-dependent effects on the MRP2-mediated transport, suggesting differences in the transport mechanism of the probes. Our results underline the complexity of substrate recognition by these efflux transporters and the difficulties in directly comparing results obtained with different assays, especially when different probes are used.
authors.affiliation: Centre for Drug Research, Faculty of Pharmacy, University of Helsinki, P.O. Box 56, 00014 Helsinki, Finland. heidi.kidron@helsinki.fi
authors.forename: Heidi
authors.initials: H
authors.lastname: Kidron
authors.forename: Gloria
authors.initials: G
authors.lastname: Wissel
authors.forename: Nenad
authors.initials: N
authors.lastname: Manevski
authors.forename: Marika
authors.initials: M
authors.lastname: Häkli
authors.forename: Raimo A
authors.initials: RA
authors.lastname: Ketola
authors.forename: Moshe
authors.initials: M
authors.lastname: Finel
authors.forename: Marjo
authors.initials: M
authors.lastname: Yliperttula
authors.forename: Henri
authors.initials: H
authors.lastname: Xhaard
authors.forename: Arto
authors.initials: A
authors.lastname: Urtti
mesh_terms: D000082:Acetaminophen / Q000494:pharmacology; D000818:Animals; D016367:Baculoviridae; D001681:Biological Assay; D001692:Biological Transport; D019819:Budesonide / Q000494:pharmacology; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D004008:Diclofenac / Q000494:pharmacology; D004206:Disopyramide / Q000494:pharmacology; D004958:Estradiol / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D004970:Estrone / Q000031:analogs & derivatives / Q000494:pharmacology; D005452:Fluoresceins / Q000493:pharmacokinetics*; D005822:Genetic Vectors; D006801:Humans; D007213:Indomethacin / Q000494:pharmacology; D020128:Inhibitory Concentration 50; D017997:Leukotriene C4 / Q000493:pharmacokinetics*; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011794:Quercetin / Q000494:pharmacology; D011994:Recombinant Proteins / Q000378:metabolism; D018411:Spodoptera; D013223:Statistics as Topic; D013881:Thioridazine / Q000494:pharmacology; D014162:Transfection
chemical_list: D000082:Acetaminophen; D019819:Budesonide; D004008:Diclofenac; D004206:Disopyramide; D004958:Estradiol; D004970:Estrone; D005452:Fluoresceins; D007213:Indomethacin; D017997:Leukotriene C4; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D011794:Quercetin; D011994:Recombinant Proteins; D013881:Thioridazine; C000715087:ABCC2 protein, human; C053897:5(6)-carboxy-2',7'-dichlorofluorescein; C025483:estradiol-17 beta-glucuronide; C017296:estrone sulfate