title: Synergistic influence of Abcb1 and Abcc2 on disposition and sterol lowering effects of ezetimibe in rats.
abstract: Pharmacokinetics of the sterol-lowering drug ezetimibe (EZ) is influenced by intestinal ABCB1 and ABCC2. This study in Lew.1W rats with "chemical" and genetic Abcb1 and Abcc2 deficiency was initiated to evaluate the individual contribution of both efflux carriers to the overall disposition and sterol-lowering effects of EZ. Disposition and sterol-lowering effects of EZ (5 mg/kg, 14 days) were measured in wild-type (WT) and Abcc2-deficient (Abcc2-) rats (N = 8 per group) and in animals treated with PSC833 (20 mg/kg) to generate "chemical" Abcb1-deficiency (Abcb1-, Abcb1-/Abcc2-). EZ serum levels decreased in the order WT (3.11 +/- 1.09 ng/mL), Abcb1- (1.94 +/- 1.10 ng/mL), Abcc2- (1.42 +/- 0.42 ng/mL, p = 0.003 vs. WT), Abcb1-/Abcc2- (1.17 +/- 0.53 ng/mL, p = 0.002 vs. WT) whereas the serum EZ glucuronide levels increased as follows: WT (23.2 +/- 24.6 ng/mL), Abcb1- (119 +/- 74.5 ng/mL, p = 0.002 vs. WT), Abcc2- (195+/-76.5 ng/mL, p < 0.001 vs. WT), Abcb1-/Abcc2- (676 +/- 207 ng/mL, p < 0.001 vs. WT, Abcb1- and Abcc2-). Abcb1 and Abcc2 protein deficiency resulted synergistically in lower fecal but increased renal excretion of total EZ although to a much lower extent. The sterol-lowering effects of EZ were significantly correlated to serum levels of EZ. In conclusion, Abcb1 and Abcc2 deficiency leads to lower levels of the active EZ and in turn to decreased sterol-lowering effects.
authors.affiliation: Department of Clinical Pharmacology Ernst Moritz Arndt University, Friedrich-Loeffler-Str 23d, D-17487 Greifswald, Germany. stefan.oswald@uni-greifswald.de
authors.forename: Stefan
authors.initials: S
authors.lastname: Oswald
authors.forename: Karen
authors.initials: K
authors.lastname: May
authors.forename: Juliane
authors.initials: J
authors.lastname: Rosin
authors.forename: Dieter
authors.initials: D
authors.lastname: Lütjohann
authors.forename: Werner
authors.initials: W
authors.lastname: Siegmund
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D018528:ATP-Binding Cassette Transporters / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D000818:Animals; D000924:Anticholesteremic Agents / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology / Q000652:urine; D001384:Azetidines / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics* / Q000494:pharmacology / Q000652:urine; D002791:Cholesterol, Dietary / Q000008:administration & dosage; D003524:Cyclosporins / Q000494:pharmacology; D000069438:Ezetimibe; D005243:Feces / Q000737:chemistry; D020719:Glucuronides / Q000378:metabolism; D008297:Male; D008657:Metabolic Clearance Rate; D051381:Rats; D011917:Rats, Inbred Lew; D013045:Species Specificity; D013261:Sterols / Q000008:administration & dosage / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D018435:ATP Binding Cassette Transporter, Subfamily B; D018528:ATP-Binding Cassette Transporters; C423013:Abcc2 protein, rat; D000924:Anticholesteremic Agents; D001384:Azetidines; D002791:Cholesterol, Dietary; D003524:Cyclosporins; D020719:Glucuronides; D013261:Sterols; C511436:ezetimibe glucuronide; C095122:multidrug resistance protein 3; D000069438:Ezetimibe; C070272:valspodar