Distribution of cholesterol between vesicles and micelles in human gallbladder bile: Influence of treatment with chenodeoxycholic acid and ursodeoxycholic acid

✍ Scribed by Dr. Staffan Sahlin; Per Thyberg; Jon Ahlberg; Bo Angelin; Kurt Einarsson

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 722 KB
• Volume: 13
• Category: Article
• ISSN: 0270-9139
• DOI: 10.1002/hep.1840130115

✦ Synopsis

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 ultracentrifugatiori, 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 vesiculrir fraction was significantly higher in the untreated gallstone group (40% f 4%) compared with the gallstone-free (28% f 3%), ursodeoxycholic acid (28% 2 3%) and chenodeoxycholic acid (18% f 4%) groups. Despite a low cholesterol saturation of bile in the latter three groups (88% f 12%, 51% -C 9% and 65% f 570, respectively), a considerable part of the biliary cholesterol was carried in the vesicular fraction. The cholesterol/phosp holipid 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 cholesterol/phospholipid ratio was about 0.15 in all micellar fractions. The nucleation time of bile from the gallstone group was short (2 f 1 days) compared with the gallstone-free, chenodeoxycholic acid and ursodeoxycholic acid groups (23 f 3,24 2 6 and 14 f 3 days, respectively). These observations give further support to the concept that the mechanism for gallstone dissolution is complex and different for chenadeoxycholic acid and ursodeoxycholic acid. (HEPATOLOCY 1991;