title: Bile salt export pump (BSEP/ABCB11) can transport a nonbile acid substrate, pravastatin.
abstract: Pravastatin is a well known 3-hydroxy-3-methylglutaryl-CoA reductase inhibitor. Cumulative studies have shown that pravastatin is taken up into hepatocytes by the organic anion transporting polypeptide family transporters and excreted into the bile as an intact form by multidrug resistance-associated protein 2 (MRP2). It is generally accepted that the bile salt export pump (BSEP/ABCB11) mainly transports bile acids and plays an indispensable role in their biliary excretion. Interestingly, we found that BSEP could accept pravastatin as a substrate. Significant ATP-dependent uptake of pravastatin by human BSEP (hBSEP)- and rat BSEP (rBsep)-expressing membrane vesicles was observed, and the ratio of the uptake activity of pravastatin to that of taurocholic acid (TCA) by hBSEP was 3.3-fold higher than that by rBsep. The K(m) value of pravastatin for hBSEP was 124 muM. A mutual inhibition study between TCA and pravastatin revealed that they competitively interact with hBSEP. Several statins inhibited the hBSEP- and rBsep-mediated uptake of TCA; however, the specific uptake of other statins (cerivastatin, fluvastatin, and pitavastatin) by hBSEP and rBSEP was not detected. The inhibitory effects of hydrophilic statins (pravastatin and rosuvastatin) on the uptake of TCA by BSEP were relatively lower than those of lipophilic statins. These data suggest that BSEP may be partly involved in the biliary excretion of pravastatin in both rats and humans.
authors.affiliation: Department of Molecular Pharmacokinetics, Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Hirano
authors.forename: Kazuya
authors.initials: K
authors.lastname: Maeda
authors.forename: Hisamitsu
authors.initials: H
authors.lastname: Hayashi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kusuhara
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Sugiyama
mesh_terms: D000074020:ATP Binding Cassette Transporter, Subfamily B, Member 11; D018528:ATP-Binding Cassette Transporters / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000502:physiology; D000256:Adenoviridae / Q000378:metabolism; D000465:Algorithms; D000818:Animals; D001693:Biological Transport, Active; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D007700:Kinetics; D017035:Pravastatin / Q000737:chemistry / Q000378:metabolism* / Q000494:pharmacology; D051381:Rats; D013656:Taurocholic Acid / Q000378:metabolism; D022161:Transport Vesicles / Q000187:drug effects / Q000378:metabolism
chemical_list: D000074020:ATP Binding Cassette Transporter, Subfamily B, Member 11; D018528:ATP-Binding Cassette Transporters; C490548:Abcb11 protein, rat; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D013656:Taurocholic Acid; D000255:Adenosine Triphosphate; D017035:Pravastatin