title: Regulation of mRNA expression of MDR1, MRP1, MRP2 and MRP3 by prototypical microsomal enzyme inducers in primary cultures of human and rat hepatocytes.
abstract: The mRNA induction of various transporters by rifampicin (Rif), dexamethasone (Dex) and omeprazole (Ome) was investigated in primary cultures of cryopreserved human and rat hepatocytes. Analysis was performed by quantitative real-time RT-PCR using primers and TaqMan probes. In primary cultures of human hepatocytes, mRNA levels of MDR and MRP1 were increased by about 1.5 fold and 1.3 fold, respectively, by exposure to Rif at 2 to 50 microM as compared with 0.1% DMSO-treated controls. MRP2 mRNA levels in the same human hepatocytes were significantly increased by 1.2 to 1.8 fold by exposure to Rif at 50 microM as compared with controls. In primary cultures of rat hepatocytes, Mdr1a and Mdr1b mRNA levels were not increased or only slightly increased at 24 hr by exposure to any of the inducers at 2, 10 or 50 microM. Mrp2 mRNA levels in the same rat hepatocytes were significantly increased by 7 to 45 fold by exposure to Dex at 2 microM as compared with controls. Based on the species differences observed in the present study, primary cultures of cryopreserved hepatocytes from both the human and rat should be useful in preclinical drug development for evaluating candidate drugs for transporter induction.
authors.affiliation: Department of Drug Metabolism, Division of Pharmacology, Drug Safety and Metabolism, Otsuka Pharmaceutical Factory Inc., Naruto, Tokushima, Japan. nisimums@otsukakj.co.jp
authors.forename: Masuhiro
authors.initials: M
authors.lastname: Nishimura
authors.forename: Akiko
authors.initials: A
authors.lastname: Koeda
authors.forename: Emako
authors.initials: E
authors.lastname: Suzuki
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Kawano
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Nakayama
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Satoh
authors.forename: Shizuo
authors.initials: S
authors.lastname: Narimatsu
authors.forename: Shinsaku
authors.initials: S
authors.lastname: Naito
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics*; D000818:Animals; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology; D004790:Enzyme Induction / Q000187:drug effects; D004791:Enzyme Inhibitors; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects*; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D026901:Membrane Transport Proteins / Q000235:genetics; D008861:Microsomes / Q000187:drug effects* / Q000201:enzymology*; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics*; D009853:Omeprazole / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012293:Rifampin / Q000494:pharmacology; D014158:Transcription, Genetic / Q000187:drug effects* / Q000235:genetics
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D003907:Dexamethasone; D004791:Enzyme Inhibitors; D026901:Membrane Transport Proteins; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D009853:Omeprazole; D012333:RNA, Messenger; D012293:Rifampin; C000715087:ABCC2 protein, human; C114462:multidrug resistance-associated protein 3; C421109:multidrug resistance-associated protein 1