title: Effects of bile salt hydrophobicity on crystallization of cholesterol in model bile.
abstract: Precipitation of cholesterol crystals is an essential step in gallstone formation. In the present study we found much faster and more extensive precipitation of various cholesterol crystal shapes in whole model biles containing the hydrophobic bile salt taurodeoxycholate than in biles containing the relatively hydrophilic taurocholate. Addition of taurodeoxycholate to isolated cholesterol-phospholipid vesicles also induced more crystallization than taurocholate. Crystallization behaviour in whole model biles and in vesicles after addition of corresponding bile salts was very similar. The very hydrophilic bile salts tauroursodeoxycholate and taurohyodeoxycholate never induced crystallization from vesicles, and crystallization in corresponding whole model biles did not occur. These bile salts also reduced crystallization dose dependently after addition of taurodeoxycholate to vesicles. Ultracentrifugation experiments suggested a higher vesicular cholesterol-phospholipid bile salts. These findings indicate that bile salt hydrophobicity influences shape of cholesterol crystals and extent of crystallization, possibly by modulating the vesicular cholesterol-phospholipid ratio.
authors.affiliation: Department of Gastroenterology, University Hospital, Utrecht, The Netherlands.
authors.forename: K J
authors.initials: KJ
authors.lastname: Van Erpecum
authors.forename: P
authors.initials: P
authors.lastname: Portincasa
authors.forename: M
authors.initials: M
authors.lastname: Gadellaa
authors.forename: B J
authors.initials: BJ
authors.lastname: Van de Heijning
authors.forename: G P
authors.initials: GP
authors.lastname: Van Berge Henegouwen
authors.forename: W
authors.initials: W
authors.lastname: Renooij
mesh_terms: D001647:Bile Acids and Salts / Q000737:chemistry*; D002769:Cholelithiasis / Q000737:chemistry* / Q000209:etiology*; D002784:Cholesterol / Q000737:chemistry*; D003460:Crystallization; D006801:Humans; D066298:In Vitro Techniques; D008954:Models, Biological; D013655:Taurochenodeoxycholic Acid / Q000737:chemistry; D013656:Taurocholic Acid / Q000737:chemistry; D013657:Taurodeoxycholic Acid / Q000031:analogs & derivatives / Q000737:chemistry
chemical_list: D001647:Bile Acids and Salts; C083510:taurohyodeoxycholic acid; D013655:Taurochenodeoxycholic Acid; D013657:Taurodeoxycholic Acid; D013656:Taurocholic Acid; C031655:ursodoxicoltaurine; D002784:Cholesterol