title: Multiple human isoforms of drug transporters contribute to the hepatic and renal transport of olmesartan, a selective antagonist of the angiotensin II AT1-receptor.
abstract: Olmesartan, a novel angiotensin II AT1-receptor antagonist, is excreted into both bile and urine, with minimal metabolism. Because olmesartan is a hydrophilic anionic compound, some transporters could be involved in its hepatic and renal clearance. In this study, we characterized the role of human drug transporters in the pharmacokinetics of olmesartan and determined the contribution of each transporter to the overall clearance of olmesartan. Olmesartan was significantly taken up into human embryonic kidney 293 cells expressing organic anion-transporting polypeptide (OATP) 1B1, OATP1B3, organic anion transporter (OAT) 1, and OAT3. We also observed its saturable uptake into human hepatocytes and kidney slices. Estimated from the relative activity factor method and application of specific inhibitors, the relative contributions of OATP1B1 and OATP1B3 to the uptake of olmesartan in human hepatocytes were almost the same, whereas OAT3 was predominantly involved in its uptake in kidney slices. The vectorial transport of olmesartan was observed in OATP1B1/multidrug resistance-associated protein (MRP) 2 double transfectants, but not in OATP1B1/multidrug resistance (MDR) 1 and OATP1B1/breast cancer resistance protein (BCRP) transfectants. ATP-dependent transport into membrane vesicles expressing human MRP2 and MRP4 was clearly observed, with K(m) values of 14.9 and 26.2 microM, respectively, whereas the urinary excretion of olmesartan in Mrp4-knockout mice was not different from that of control mice. We also investigated the transcellular transport of olmesartan medoxomil, a prodrug of olmesartan. Vectorial basal-to-apical transport was observed in OATP1B1/MRP2, OATP1B1/MDR1 double, and OATP1B1/BCRP double transfectants, suggesting the possible involvement of MRP2, MDR1, and BCRP in the limit of intestinal absorption of olmesartan medoxomil. From these results, we suggest that multiple transporters make a significant contribution to the pharmacokinetics of olmesartan and its prodrug.
authors.affiliation: Department of Molecular Pharmacokinetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Yamada
authors.forename: Kazuya
authors.initials: K
authors.lastname: Maeda
authors.forename: Emi
authors.initials: E
authors.lastname: Kamiyama
authors.forename: Daisuke
authors.initials: D
authors.lastname: Sugiyama
authors.forename: Tsunenori
authors.initials: T
authors.lastname: Kondo
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Shiroyanagi
authors.forename: Hayakazu
authors.initials: H
authors.lastname: Nakazawa
authors.forename: Teruo
authors.initials: T
authors.lastname: Okano
authors.forename: Masashi
authors.initials: M
authors.lastname: Adachi
authors.forename: John D
authors.initials: JD
authors.lastname: Schuetz
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Adachi
authors.forename: Zhuohan
authors.initials: Z
authors.lastname: Hu
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kusuhara
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Sugiyama
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B; D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000378:metabolism; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D047228:Angiotensin II Type 1 Receptor Blockers / Q000378:metabolism* / Q000493:pharmacokinetics; D000818:Animals; D002460:Cell Line; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004970:Estrone / Q000031:analogs & derivatives / Q000378:metabolism; D005260:Female; D022781:Hepatocytes / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007093:Imidazoles / Q000378:metabolism* / Q000493:pharmacokinetics; D066298:In Vitro Techniques; D007668:Kidney / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D027381:Liver-Specific Organic Anion Transporter 1; D026901:Membrane Transport Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000172:deficiency / Q000378:metabolism; D009363:Neoplasm Proteins / Q000378:metabolism; D000068557:Olmesartan Medoxomil; D027361:Organic Anion Transporters / Q000378:metabolism; D029362:Organic Anion Transporters, Sodium-Independent / Q000378:metabolism; D010400:Penicillin G / Q000494:pharmacology; D011339:Probenecid / Q000494:pharmacology; D011355:Prodrugs / Q000378:metabolism* / Q000493:pharmacokinetics; D011485:Protein Binding; D020033:Protein Isoforms / Q000378:metabolism; D012844:Sincalide / Q000378:metabolism; D000074542:Solute Carrier Organic Anion Transporter Family Member 1B3; D013777:Tetrazoles / Q000378:metabolism* / Q000493:pharmacokinetics; D014162:Transfection; D010130:p-Aminohippuric Acid / Q000494:pharmacology