title: Estradiol-17beta-D-glucuronide induces endocytic internalization of Bsep in rats.
abstract: Endocytic internalization of the multidrug resistance-associated protein 2 (Mrp2) was previously suggested to be involved in estradiol-17beta-D-glucuronide (E217G)-induced cholestasis. Here we evaluated in the rat whether a similar phenomenon occurs with the bile salt export pump (Bsep) and the ability of DBcAMP to prevent it. E217G (15 micromol/kg i.v.) impaired bile salt (BS) output and induced Bsep internalization, as assessed by confocal microscopy and Western blotting. Neither cholestasis nor Bsep internalization occurred in TR- rats lacking Mrp2. DBcAMP (20 micromol/kg i.v.) partially prevented the decrease in bile flow and BS output and substantially prevented E217G-induced Bsep internalization. In hepatocyte couplets, E217G (50 microM) diminished canalicular accumulation of a fluorescent BS and decreased Bsep-associated fluorescence in the canalicular membrane; DBcAMP (10 microM) fully prevented both effects. In conclusion, our results suggest that changes in Bsep localization are involved in E217G-induced impairment of bile flow and BS transport and that DBcAMP prevents this effect by stimulating insertion of canalicular transporter-containing vesicles. Mrp2 is required for E217G to induce its harmful effect.
authors.affiliation: Instituto de Fisiología Experimental, Universidad Nacional de Rosario, Argentina.
authors.forename: Fernando A
authors.initials: FA
authors.lastname: Crocenzi
authors.forename: Aldo D
authors.initials: AD
authors.lastname: Mottino
authors.forename: Jingsong
authors.initials: J
authors.lastname: Cao
authors.forename: Luis M
authors.initials: LM
authors.lastname: Veggi
authors.forename: Enrique J Sánchez
authors.initials: EJ
authors.lastname: Pozzi
authors.forename: Mary
authors.initials: M
authors.lastname: Vore
authors.forename: Roger
authors.initials: R
authors.lastname: Coleman
authors.forename: Marcelo G
authors.initials: MG
authors.lastname: Roma
mesh_terms: D000074020:ATP Binding Cassette Transporter, Subfamily B, Member 11; D018528:ATP-Binding Cassette Transporters / Q000032:analysis / Q000378:metabolism*; D000199:Actins / Q000032:analysis; D000818:Animals; D001646:Bile / Q000502:physiology; D001647:Bile Acids and Salts / Q000378:metabolism; D001648:Bile Canaliculi / Q000737:chemistry; D015153:Blotting, Western; D003994:Bucladesine / Q000494:pharmacology; D002352:Carrier Proteins / Q000235:genetics / Q000502:physiology; D002462:Cell Membrane / Q000737:chemistry; D002779:Cholestasis / Q000378:metabolism; D004705:Endocytosis / Q000187:drug effects*; D004958:Estradiol / Q000031:analogs & derivatives* / Q000494:pharmacology*; D005260:Female; D005455:Fluorescent Antibody Technique; D008099:Liver / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D018613:Microscopy, Confocal; D009154:Mutation; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar
chemical_list: D000074020:ATP Binding Cassette Transporter, Subfamily B, Member 11; D018528:ATP-Binding Cassette Transporters; C490548:Abcb11 protein, rat; C423013:Abcc2 protein, rat; D000199:Actins; D001647:Bile Acids and Salts; D002352:Carrier Proteins; C025483:estradiol-17 beta-glucuronide; D004958:Estradiol; D003994:Bucladesine