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Critical Differences between Enzyme Sources in Sensitivity to Detect Time-Dependent Inactivation of CYP2C8.
Kahma, Helinä; Filppula, Anne M; Launiainen, Terhi; Viinamäki, Jenni; Neuvonen, Mikko; Evangelista, Eric A; Totah, Rheem A; Backman, Janne T.
Affiliation
  • Kahma H; Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, and Department of Clinical Pharmacology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland (H.K., A.M.F., T.L., J.V., M.N., J.T.B.) and Department of Medicinal Chemistry, University of
  • Filppula AM; Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, and Department of Clinical Pharmacology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland (H.K., A.M.F., T.L., J.V., M.N., J.T.B.) and Department of Medicinal Chemistry, University of
  • Launiainen T; Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, and Department of Clinical Pharmacology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland (H.K., A.M.F., T.L., J.V., M.N., J.T.B.) and Department of Medicinal Chemistry, University of
  • Viinamäki J; Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, and Department of Clinical Pharmacology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland (H.K., A.M.F., T.L., J.V., M.N., J.T.B.) and Department of Medicinal Chemistry, University of
  • Neuvonen M; Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, and Department of Clinical Pharmacology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland (H.K., A.M.F., T.L., J.V., M.N., J.T.B.) and Department of Medicinal Chemistry, University of
  • Evangelista EA; Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, and Department of Clinical Pharmacology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland (H.K., A.M.F., T.L., J.V., M.N., J.T.B.) and Department of Medicinal Chemistry, University of
  • Totah RA; Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, and Department of Clinical Pharmacology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland (H.K., A.M.F., T.L., J.V., M.N., J.T.B.) and Department of Medicinal Chemistry, University of
  • Backman JT; Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, and Department of Clinical Pharmacology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland (H.K., A.M.F., T.L., J.V., M.N., J.T.B.) and Department of Medicinal Chemistry, University of
Drug Metab Dispos ; 47(4): 436-443, 2019 04.
Article in En | MEDLINE | ID: mdl-30709838
ABSTRACT
Clopidogrel acyl-ß-d-glucuronide is a mechanism-based inhibitor of cytochrome P450 2C8 in human liver microsomes (HLMs). However, time-dependent inactivation (TDI) of CYP2C8 could not be detected in an earlier study in human recombinant CYP2C8 (Supersomes). Here, we investigate whether different enzyme sources exhibit differences in detection of CYP2C8 TDI under identical experimental conditions. Inactivation of CYP2C8 by amiodarone (100 µM), clopidogrel acyl-ß-d-glucuronide (100 µM), gemfibrozil 1-O-ß-glucuronide (100 µM), and phenelzine (100 µM) was investigated in HLMs and three recombinant human CYP2C8 preparations (Supersomes, Bactosomes, and EasyCYP Bactosomes) using amodiaquine N-deethylation as the marker reaction. Furthermore, the inactivation kinetics of CYP2C8 by clopidogrel glucuronide (5-250 µM) was determined in Supersomes and Bactosomes. Amiodarone caused weak TDI in all enzyme preparations tested, while the extent of inactivation by clopidogrel glucuronide, gemfibrozil glucuronide, and phenelzine varied markedly between preparations, and even different Supersome lots. Both glucuronides caused strong inactivation of CYP2C8 in HLMs, Bactosomes and in one Supersome lot (>50% inhibition), but significant inactivation could not be reliably detected in other Supersome lots or EasyCYP Bactosomes. In Bactosomes, the concentration producing half of kinact (KI) and maximal inactivation rate (kinact) of clopidogrel glucuronide (14 µM and 0.054 minute-1) were similar to those determined previously in HLMs. Phenelzine caused strong inactivation of CYP2C8 in one Supersome lot (91% inhibition) but not in HLMs or other recombinant CYP2C8 preparations. In conclusion, different enzyme sources and different lots of the same recombinant enzyme preparation are not equally sensitive to detect inactivation of CYP2C8, suggesting that recombinant CYPs should be avoided when identifying mechanism-based inhibitors.
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Full text: 1 Collection: 01-internacional Database: MEDLINE Main subject: Cytochrome P-450 CYP2C8 Type of study: Diagnostic_studies Limits: Humans Language: En Journal: Drug Metab Dispos Journal subject: FARMACOLOGIA Year: 2019 Type: Article
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Full text: 1 Collection: 01-internacional Database: MEDLINE Main subject: Cytochrome P-450 CYP2C8 Type of study: Diagnostic_studies Limits: Humans Language: En Journal: Drug Metab Dispos Journal subject: FARMACOLOGIA Year: 2019 Type: Article