TY - JOUR T1 - Utility of Oatp1a/1b-Knockout and OATP1B1/3-Humanized Mice in the Study of OATP-Mediated Pharmacokinetics and Tissue Distribution: Case Studies with Pravastatin, Atorvastatin, Simvastatin, and Carboxydichlorofluorescein JF - Drug Metabolism and Disposition JO - Drug Metab Dispos SP - 182 LP - 192 DO - 10.1124/dmd.113.054783 VL - 42 IS - 1 AU - J. William Higgins AU - Jing Q. Bao AU - Alice B. Ke AU - Jason R. Manro AU - John K. Fallon AU - Philip C. Smith AU - Maciej J. Zamek-Gliszczynski Y1 - 2014/01/01 UR - http://dmd.aspetjournals.org/content/42/1/182.abstract N2 - Although organic anion transporting polypeptide (OATP)–mediated hepatic uptake is generally conserved between rodents and humans at a gross pharmacokinetic level, the presence of three major hepatic OATPs with broad overlap in substrate and inhibitor affinity, and absence of rodent-human orthologs preclude clinical translation of single-gene knockout/knockin findings. At present, changes in pharmacokinetics and tissue distribution of pravastatin, atorvastatin, simvastatin, and carboxydichlorofluorescein were studied in oatp1a/1b-knockout mice lacking the three major hepatic oatp isoforms, and in knockout mice with liver-specific knockin of human OATP1B1 or OATP1B3. Relative to wild-type controls, oatp1a/1b-knockout mice exhibited 1.6- to 19-fold increased intravenous and 2.1- to 115-fold increased oral drug exposure, due to 33%–75% decreased clearance, 14%–60% decreased volume of distribution, and ≤74-fold increased oral bioavailability, with the magnitude of change depending on the contribution of oatp1a/1b to pharmacokinetics. Hepatic drug distribution was 4.2- to 196-fold lower in oatp1a/1b-knockout mice; distributional attenuation was less notable in kidney, brain, cardiac, and skeletal muscle. Knockin of OATP1B1 or OATP1B3 partially restored control clearance, volume, and bioavailability values (24%–142% increase, ≤47% increase, and ≤77% decrease vs. knockout, respectively), such that knockin pharmacokinetic profiles were positioned between knockout and wild-type mice. Consistent with liver-specific humanization, only hepatic drug distribution was partially restored (1.3- to 6.5-fold increase vs. knockout). Exposure and liver distribution changes in OATP1B1-humanized versus knockout mice predicted the clinical impact of OATP1B1 on oral exposure and contribution to human hepatic uptake of statins within 1.7-fold, but only after correcting for human/humanized mouse liver relative protein expression factor (OATP1B1 = 2.2, OATP1B3 = 0.30). ER -