title: Distribution of cholesterol between vesicles and micelles in human gallbladder bile: influence of treatment with chenodeoxycholic acid and ursodeoxycholic acid.
abstract: The present study aimed at determining the relative distribution of cholesterol between the vesicular and micellar phases in gallbladder bile of gallstone patients (n = 23) and gallstone-free subjects (n = 7). Nine of the gallstone patients were treated with chenodeoxycholic acid and seven were treated with ursodeoxycholic acid, 15 mg/kg/day, for 3 wk before cholecystectomy. The vesicular and micellar fractions in bile were separated by sucrose density gradient ultracentrifugation, and a clear separation between the two phases was obtained. The vesicles were further identified by quasielastic light scattering spectroscopy and appeared to be of a uniform size with a mean hydrodynamic radius of 760 A. The proportion of cholesterol in the vesicular fraction was significantly higher in the untreated gallstone group (40% +/- 4%) compared with the gallstone-free (28% +/- 3%), ursodeoxycholic acid (28% +/- 3%) and chenodeoxycholic acid (18% +/- 4%) groups. Despite a low cholesterol saturation of bile in the latter three groups (88% +/- 12%, 51% +/- 9% and 65% +/- 5%, respectively), a considerable part of the biliary cholesterol was carried in the vesicular fraction. The cholesterol/phospholipid ratio in the vesicular fraction averaged between 0.49 and 0.58 in the gallstone, gallstone-free and chenodeoxycholic acid groups, whereas the ursodeoxycholic acid group had a significantly lower ratio of 0.24. The nucleation time of bile from the gallstone group was short (2 +/- 1 days) compared with the gallstone-free, chenodeoxycholic acid and ursodeoxycholic acid groups (23 +/- 3, 24 +/- 6 and 14 +/- 3 days, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Surgery, Danderyd Hospital, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Sahlin
authors.forename: P
authors.initials: P
authors.lastname: Thyberg
authors.forename: J
authors.initials: J
authors.lastname: Ahlberg
authors.forename: B
authors.initials: B
authors.lastname: Angelin
authors.forename: K
authors.initials: K
authors.lastname: Einarsson
mesh_terms: D000328:Adult; D001646:Bile / Q000737:chemistry*; D002499:Centrifugation, Density Gradient; D002635:Chenodeoxycholic Acid / Q000494:pharmacology*; D002769:Cholelithiasis / Q000378:metabolism; D002784:Cholesterol / Q000032:analysis*; D003460:Crystallization; D005260:Female; D005704:Gallbladder / Q000737:chemistry; D006801:Humans; D008055:Lipids / Q000032:analysis; D008297:Male; D008823:Micelles; D008875:Middle Aged; D010743:Phospholipids / Q000032:analysis; D013057:Spectrum Analysis; D014580:Ursodeoxycholic Acid / Q000494:pharmacology*
chemical_list: D008055:Lipids; D008823:Micelles; D010743:Phospholipids; D002635:Chenodeoxycholic Acid; D014580:Ursodeoxycholic Acid; D002784:Cholesterol