title: Interaction of fluvastatin with the liver-specific Na+ -dependent taurocholate cotransporting polypeptide (NTCP).
abstract: It has been reported that polymorphisms in the organic anion transporting polypeptide 1B1 (OATP1B1, SLCO1B1) result in decreased hepatic uptake of simvastatin carboxy acid, the active metabolite of simvastatin. This is not the case for fluvastatin and it has been hypothesized that for this drug other hepatic uptake pathways exist. Here, we studied whether Na(+)-dependent taurocholate co-transporting polypeptide (NTCP, SLC10A1) can be an alternative hepatic uptake route for fluvastatin. Chinese Hamster Ovary cells transfected with human NTCP (CHO-NTCP) were used to investigate the inhibitory effect of fluvastatin and other statins on [(3)H]-taurocholic acid uptake ([(3)H]-TCA). Statin uptake by CHO-NTCP and cryopreserved human hepatocytes was assessed via LC-MS/MS. Fluvastatin appeared to be a potent and competitive inhibitor of [(3)H]-TCA uptake (IC(50) of 40μM), pointing to an interaction at the level of the bile acid binding pocket of NTCP. The inhibitory action of other statins was also studied, which revealed that statin inhibitory potency increased with molecular descriptors of lipophilicity: calculated logP (r(2)=0.82, p=0.034), logD(7.4) (r(2)=0.77, p=0.0001). Studies in CHO-NTCP cells showed that fluvastatin was indeed an NTCP substrate (K(m) 250±30μM, V(max) 1340±50ng/mg total cell protein/min). However, subsequent studies revealed that at clinically relevant plasma concentrations, NTCP contributed minimally to overall accumulation in human hepatocytes. In conclusion, fluvastatin interacts with NTCP at the level of the bile acid binding pocket and is an NTCP substrate. However, under normal conditions, NTCP-mediated uptake of this drug seems not to be a significant hepatocellular uptake pathway.
authors.affiliation: Department of Pharmacology and Toxicology, Radboud University Nijmegen Medical Centre, Nijmegen Centre for Molecular Life Sciences, The Netherlands.
authors.forename: Rick
authors.initials: R
authors.lastname: Greupink
authors.forename: Lieve
authors.initials: L
authors.lastname: Dillen
authors.forename: Mario
authors.initials: M
authors.lastname: Monshouwer
authors.forename: Maarten T
authors.initials: MT
authors.lastname: Huisman
authors.forename: Frans G M
authors.initials: FG
authors.lastname: Russel
mesh_terms: D000818:Animals; D001667:Binding, Competitive; D001692:Biological Transport / Q000187:drug effects; D016466:CHO Cells; D002478:Cells, Cultured; D006224:Cricetinae; D004958:Estradiol / Q000031:analogs & derivatives / Q000378:metabolism; D005229:Fatty Acids, Monounsaturated / Q000378:metabolism* / Q000494:pharmacology; D000077340:Fluvastatin; D022781:Hepatocytes / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000378:metabolism / Q000494:pharmacology; D007211:Indoles / Q000378:metabolism* / Q000494:pharmacology; D020128:Inhibitory Concentration 50; D007700:Kinetics; D027381:Liver-Specific Organic Anion Transporter 1; D015394:Molecular Structure; D027361:Organic Anion Transporters / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D029363:Organic Anion Transporters, Sodium-Dependent / Q000235:genetics / Q000378:metabolism*; D012293:Rifampin / Q000494:pharmacology; D019821:Simvastatin / Q000378:metabolism / Q000494:pharmacology; D012964:Sodium / Q000172:deficiency / Q000378:metabolism; D027981:Symporters / Q000235:genetics / Q000378:metabolism*; D013656:Taurocholic Acid / Q000378:metabolism; D014162:Transfection
chemical_list: D005229:Fatty Acids, Monounsaturated; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D007211:Indoles; D027381:Liver-Specific Organic Anion Transporter 1; D027361:Organic Anion Transporters; D029363:Organic Anion Transporters, Sodium-Dependent; C503999:SLCO1B1 protein, human; D027981:Symporters; C071908:sodium-bile acid cotransporter; C025483:estradiol-17 beta-glucuronide; D000077340:Fluvastatin; D004958:Estradiol; D013656:Taurocholic Acid; D012964:Sodium; D019821:Simvastatin; D012293:Rifampin