title: Screening of OATP1B1/3 and OCT1 inhibitors in cryopreserved hepatocytes in suspension.
abstract: Drug-drug interactions involving hepatic drug transporters may have clinical consequences and jeopardize development of promising drug candidates. Organic anion transporting polypeptides (OATP/Oatp) and the organic cation transporters (OCT/Oct) are among the most important transporters involved in xenobiotic uptake in the liver. In the present study, 179 molecules have been tested as inhibitors of the uptake of estradiol-17betaD-glucuronide (E(2)17betaG), substrate of OATP1B1/3 (rOatp), or 1-methyl-4-phenylpyridinium (MPP+), substrate of OCT1 (rOct1), into suspended cryopreserved hepatocytes from humans and rats. Uptake was assessed in 96-well plates by measuring intracellular accumulation of radioactive substrate in hepatocytes in presence or absence of inhibitor. In rat hepatocytes 140 compounds were identified as inhibitors (inhibition at 20 microM > or = 30%) of E(2)17betaG uptake and 77 compounds inhibitors of MPP+ uptake. The most potent inhibitors of rOatp and rOct1 were dantrolene sodium (K(i)=2 +/- 9 microM) and bepridil (K(i)=14 +/- 2 microM), respectively. In human hepatocytes, the most potent inhibitors of E(2)17betaG and MPP+ uptake were capsazepine (K(i)=14 +/- 5 microM) and cyproheptadine (K(i)=19+/-3 microM), respectively. Structure-activity relationship (SAR) analysis of all tested compounds suggested that lipophilicity, polarity, pK(a) and the number of hydrogen bond donors and acceptors play a role in their interaction with the transporters investigated. The method used here is a simple tool to screen large number of compounds as inhibitors of the uptake of substrates into suspended hepatocytes.
authors.affiliation: Department of Discovery ADME, H. Lundbeck A/S, Ottiliavej 9, 2500 Valby, Denmark. laba@lundbeck.com
authors.forename: Lassina
authors.initials: L
authors.lastname: Badolo
authors.forename: Louise Munk
authors.initials: LM
authors.lastname: Rasmussen
authors.forename: Helle Rüsz
authors.initials: HR
authors.lastname: Hansen
authors.forename: Christina
authors.initials: C
authors.lastname: Sveigaard
mesh_terms: D015655:1-Methyl-4-phenylpyridinium / Q000493:pharmacokinetics*; D000818:Animals; D015764:Bepridil / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D002211:Capsaicin / Q000031:analogs & derivatives / Q000494:pharmacology; D015925:Cryopreservation; D003533:Cyproheptadine / Q000494:pharmacology; D003620:Dantrolene / Q000494:pharmacology; D004353:Drug Evaluation, Preclinical; D004347:Drug Interactions; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D004958:Estradiol / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D022781:Hepatocytes / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors; D027381:Liver-Specific Organic Anion Transporter 1; D027361:Organic Anion Transporters / Q000037:antagonists & inhibitors*; D029362:Organic Anion Transporters, Sodium-Independent / Q000037:antagonists & inhibitors*; D051381:Rats; D000074542:Solute Carrier Organic Anion Transporter Family Member 1B3; D013045:Species Specificity; D013329:Structure-Activity Relationship
chemical_list: D004791:Enzyme Inhibitors; D007527:Isoenzymes; D027381:Liver-Specific Organic Anion Transporter 1; D027361:Organic Anion Transporters; D029362:Organic Anion Transporters, Sodium-Independent; C503999:SLCO1B1 protein, human; C421209:SLCO1B3 protein, human; D000074542:Solute Carrier Organic Anion Transporter Family Member 1B3; C025483:estradiol-17 beta-glucuronide; D003533:Cyproheptadine; D004958:Estradiol; D015764:Bepridil; D003620:Dantrolene; C071423:capsazepine; D015655:1-Methyl-4-phenylpyridinium; D002211:Capsaicin