Impact of Experimental Conditions on the Evaluation of Interactions between Multidrug and Toxin Extrusion Proteins and Candidate Drugs

摘要: Multidrug and toxin extrusion transporters (MATEs) have a determining influence on the pharmacokinetic profiles of many drugs are involved in several clinical drug-drug interactions (DDIs). Cellular uptake assays with recombinant cells expressing human MATE1 or MATE2-K widely used to investigate MATE-mediated transport for DDI assessment; however, experimental conditions test substrates vary among laboratories. We therefore initially examined impact three assay that been applied MATE substrate inhibitor profiling literature. One tested resulted significantly higher rates substrates, [(14)C]metformin, [(3)H]thiamine, [(3)H]1-methyl-4-phenylpyridinium (MPP(+)), but IC50 values four inhibitors varied only slightly (<2.5-fold difference). Subsequently, we investigated characteristics five substrates: [(3)H]MPP(+), [(3)H]estrone-3-sulfate (E3S), rhodamine 123, as well inhibition 10 at one selected condition. [(3)H]E3S showed atypical compared those observed other substrates. were similar range (<4-fold difference) when considerably 123 (9.8-fold 4.1-fold differences [(14)C]metformin MATE2-K, respectively). This study demonstrated first time determination is negligible, kinetic differ substrate-dependent exists giving valuable insight into assessment clinically relevant DDIs vitro.