title: Inhibitory effects of p-aminohippurate and probenecid on the renal clearance of adefovir and benzylpenicillin as probe drugs for organic anion transporter (OAT) 1 and OAT3 in humans.
abstract: Probe substrates for, and inhibitors of, specific transporters are desired to evaluate quantitatively the in vivo functions of transporters in humans. Based on published data, adefovir and benzylpenicillin were selected as organic anion transporter (OAT) 1- and OAT3-selective probe substrates, respectively. In human kidney slices, probenecid potently inhibited the uptake of both adefovir and benzylpenicillin with inhibition constant (Ki) values of 18.6±5.1 and 12.6±4.2μM, respectively, whereas p-aminohippurate (PAH) preferentially inhibited adefovir uptake. A clinical drug-interaction study involving healthy subjects was performed to investigate the dose-dependent inhibition potencies of probenecid and PAH on the renal clearance of the probe substrates. Adefovir or benzylpenicillin was coadministered with different oral doses of probenecid (500, 750, or 1500mg) or intravenous PAH infusion rates (70, 120, or 210mg/min/person) to the same subject using a crossover design. The renal clearance of adefovir was reduced by 45% and 46% in the subjects treated with the maximum dose of probenecid and PAH, respectively, which was in accordance with the results of in vitro inhibition study. On the other hand, renal clearance of benzylpenicillin was reduced by 78% in the subjects treated with the maximum dose of probenecid (1500mg), which could be explained by its in vitro Ki values. However, PAH unexpectedly increased the renal clearance of benzylpenicillin by 47%. These results suggest that adefovir and benzylpenicillin can be used as probe drugs for OAT1 and OAT3, respectively, and that PAH can be used to investigate the role of OAT1 in the urinary excretion of drugs in humans, whereas it may modulate other transport processes in the kidney.
authors.affiliation: Department of Molecular Pharmacokinetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Maeda
authors.affiliation: Department of Molecular Pharmacokinetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Ying
authors.initials: Y
authors.lastname: Tian
authors.affiliation: Clinical Trial Center, Kitasato University East Hospital, 2-1-1 Asamizodai, Minami-ku, Sagamihara City, Kanagawa 252-0380, Japan.
authors.forename: Tomoe
authors.initials: T
authors.lastname: Fujita
authors.affiliation: Clinical Trial Center, Kitasato University East Hospital, 2-1-1 Asamizodai, Minami-ku, Sagamihara City, Kanagawa 252-0380, Japan.
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Ikeda
authors.affiliation: Clinical Trial Center, Kitasato University East Hospital, 2-1-1 Asamizodai, Minami-ku, Sagamihara City, Kanagawa 252-0380, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kumagai
authors.affiliation: Department of Urology, Tokyo Women's Medical University, 8-1 Kawada-Cho, Shinjuku-ku, Tokyo 162-8666, Japan.
authors.forename: Tsunenori
authors.initials: T
authors.lastname: Kondo
authors.affiliation: Department of Urology, Tokyo Women's Medical University, 8-1 Kawada-Cho, Shinjuku-ku, Tokyo 162-8666, Japan.
authors.forename: Kazunari
authors.initials: K
authors.lastname: Tanabe
authors.affiliation: Department of Urology, Tokyo Women's Medical University, 8-1 Kawada-Cho, Shinjuku-ku, Tokyo 162-8666, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Nakayama
authors.affiliation: Department of Urology, Tokyo Women's Medical University, 8-1 Kawada-Cho, Shinjuku-ku, Tokyo 162-8666, Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Horita
authors.affiliation: Department of Molecular Pharmacokinetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kusuhara
authors.affiliation: Sugiyama Laboratory, RIKEN Innovation Center, RIKEN Research Cluster for Innovation, RIKEN, 1-6 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan. Electronic address: ychi.sugiyama@riken.jp.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Sugiyama
mesh_terms: D000225:Adenine / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics; D000328:Adult; D004347:Drug Interactions; D057809:HEK293 Cells; D006801:Humans; D066298:In Vitro Techniques; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D027362:Organic Anion Transport Protein 1 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D029362:Organic Anion Transporters, Sodium-Independent / Q000037:antagonists & inhibitors* / Q000378:metabolism; D063065:Organophosphonates / Q000097:blood / Q000493:pharmacokinetics*; D010400:Penicillin G / Q000097:blood / Q000493:pharmacokinetics*; D011339:Probenecid / Q000494:pharmacology*; D055815:Young Adult; D010130:p-Aminohippuric Acid / Q000494:pharmacology*
chemical_list: D027362:Organic Anion Transport Protein 1; D029362:Organic Anion Transporters, Sodium-Independent; D063065:Organophosphonates; C114338:organic anion transport protein 3; C053001:adefovir; D000225:Adenine; D011339:Probenecid; D010400:Penicillin G; D010130:p-Aminohippuric Acid
keywords: Adefovir; Benzylpenicillin; Organic anion transporter (OAT); Probe drug; Renal clearance