title: Human organic anion transporters and human organic cation transporters mediate renal antiviral transport.
abstract: Renal excretion is an important elimination pathway for antiviral agents, such as acyclovir (ACV), ganciclovir (GCV), and zidovudine (AZT). The purpose of this study was to elucidate the molecular mechanisms of renal ACV, GCV, and AZT transport using cells stably expressing human organic anion transporter 1 (hOAT1), hOAT2, hOAT3, and hOAT4, and human organic cation transporter 1 (hOCT1) and hOCT2. Time- and concentration-dependent uptake of ACV and GCV was observed in hOAT1- and hOCT1-expressing cells. In contrast, uptake of valacyclovir, L-valyl ester of ACV, was observed only in hOAT3-expressing cells. On the other hand, AZT uptake was observed in hOAT1-, hOAT2-, hOAT3-, and hOAT4-expressing cells. The Km values of ACV uptake by hOAT1 and hOCT1 were 342.3 and 151.2 microM, respectively, whereas those of GCV uptake by hOAT1 and hOCT1 were 895.5 and 516.2 microM, respectively. On the other hand, the Km values of AZT uptake by hOAT1, hOAT2, hOAT3, and hOAT4 were 45.9, 26.8, 145.1, and 151.8 microM, respectively. In addition, probenecid weakly inhibited the hOAT1-mediated ACV uptake. In conclusion, these results suggest that hOAT1 and hOCT1 mediate renal ACV and GCV transport, whereas hOAT1, hOAT2, hOAT3, and hOAT4 mediate renal AZT transport. In addition, L-valyl ester appears to be important in differential substrate recognition between hOAT1 and hOAT3. hOAT1 may not be the molecule responsible for the drug interaction between ACV and probenecid.
authors.affiliation: Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Tokyo, Japan.
authors.forename: Michio
authors.initials: M
authors.lastname: Takeda
authors.forename: Suparat
authors.initials: S
authors.lastname: Khamdang
authors.forename: Shinichi
authors.initials: S
authors.lastname: Narikawa
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kimura
authors.forename: Yasuna
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Toshinori
authors.initials: T
authors.lastname: Yamamoto
authors.forename: Seok Ho
authors.initials: SH
authors.lastname: Cha
authors.forename: Takashi
authors.initials: T
authors.lastname: Sekine
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Endou
mesh_terms: D000212:Acyclovir / Q000378:metabolism; D019380:Anti-HIV Agents / Q000378:metabolism; D000998:Antiviral Agents / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D002478:Cells, Cultured; D015774:Ganciclovir / Q000378:metabolism; D006801:Humans; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D027361:Organic Anion Transporters / Q000037:antagonists & inhibitors / Q000378:metabolism*; D027701:Organic Cation Transport Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011339:Probenecid / Q000494:pharmacology; D012076:Renal Agents / Q000494:pharmacology; D015215:Zidovudine / Q000378:metabolism
chemical_list: D019380:Anti-HIV Agents; D000998:Antiviral Agents; D027361:Organic Anion Transporters; D027701:Organic Cation Transport Proteins; D012076:Renal Agents; D015215:Zidovudine; D015774:Ganciclovir; D011339:Probenecid; D000212:Acyclovir