title: S-8921, an ileal Na+/bile acid cotransporter inhibitor decreases serum cholesterol in hamsters.
abstract: The ileal Na+/bile acid cotransporter (IBAT) maintains the reabsorption of bile acids from the intestine in the enterohepatic circulation of bile acids. In the present study, we showed that S-8921 could dose-dependently inhibit the uptake of [3H] taurocholate in the COS7 cell line which constitutively expresses hamster IBAT. The IC50 value of S-8921 against 60 microM of [3H] taurocholate uptake was 66 +/- 8 microM and kinetic analysis revealed that the inhibition by 100 microM of S-8921 was a mixture of competitive and non-competitive types. In vivo administration of S-8921 by its incorporation into diet (0.001-0.1%) caused dose-dependent decrease of serum cholesterol concentrations accompanied by increased fecal excretion of bile acids in hamsters which were not loaded with cholesterol and bile acid. These data suggest that the inhibition of IBAT could decrease serum cholesterol in the non-cholesterol and -bile acid loaded normal condition.
authors.affiliation: Discovery Research Laboratories II, Shionogi & Co., Ltd., Toyonaka, Osaka, Japan. seijiro.hara@shionogi.co.jp
authors.forename: S
authors.initials: S
authors.lastname: Hara
authors.forename: J
authors.initials: J
authors.lastname: Higaki
authors.forename: K
authors.initials: K
authors.lastname: Higashino
authors.forename: M
authors.initials: M
authors.lastname: Iwai
authors.forename: N
authors.initials: N
authors.lastname: Takasu
authors.forename: K
authors.initials: K
authors.lastname: Miyata
authors.forename: K
authors.initials: K
authors.lastname: Tonda
authors.forename: K
authors.initials: K
authors.lastname: Nagata
authors.forename: Y
authors.initials: Y
authors.lastname: Goh
authors.forename: T
authors.initials: T
authors.lastname: Mizui
mesh_terms: D000042:Absorption; D000818:Animals; D000924:Anticholesteremic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001835:Body Weight / Q000187:drug effects; D019556:COS Cells; D002352:Carrier Proteins / Q000037:antagonists & inhibitors*; D002784:Cholesterol / Q000097:blood*; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D015243:Cholesterol, VLDL / Q000097:blood; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D009284:Naphthols / Q000008:administration & dosage / Q000494:pharmacology*; D029363:Organic Anion Transporters, Sodium-Dependent; D027981:Symporters; D013656:Taurocholic Acid / Q000493:pharmacokinetics
chemical_list: D000924:Anticholesteremic Agents; D002352:Carrier Proteins; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D015243:Cholesterol, VLDL; D009284:Naphthols; D029363:Organic Anion Transporters, Sodium-Dependent; D027981:Symporters; C071908:sodium-bile acid cotransporter; C106517:S 8921; D013656:Taurocholic Acid; D002784:Cholesterol