Effect of gallbladder mucin on the crystallization of cholesterol in bile.
OBJECTIVE
Mucin is supposed to accelerate the crystallization of cholesterol in model bile while studies in native human gallbladder bile revealed conflicting results.


METHODS
Therefore, we determined the relation of mucin concentration and cholesterol crystal observation time in gallbladder bile of 73 patients with cholesterol and mixed and 21 patients with pigment stones. In addition, bile samples of 20 patients with cholesterol gallstones were supplemented with either 0 (control) or 0.5-4.0 mg/ml purified bovine mucin or human mucin isolated from gallbladder bile, to study the effect of variable mucin concentrations on the crystallization of cholesterol.


RESULTS
Rapid nucleating biles (</= 4 days, n = 59) showed higher mucin concentrations (0.73 +/- 0.1 mg/ml vs 0.43 +/- 0.07 mg/ml) than biles with longer (> 4 days, n = 35) cholesterol crystal observation times (P < 0.05), but no correlation between mucin concentration and cholesterol crystal observation time was observed. Supplementation experiments with bovine purified mucin (up to 4.0 mg/ml) showed no significant effect on the total amount of newly formed cholesterol crystals within 21 days. However, higher amounts of newly formed cholesterol crystals were seen in bile samples supplemented with human mucin in comparison to negative controls.


CONCLUSIONS
Our results demonstrate a dose-dependent effect of human but not of bovine gallbladder mucin on the formation of cholesterol monohydrate crystals in gallbladder bile of patients with cholesterol stones. Therefore, studies of cholesterol crystallization in model bile systems may be valuable but should always be confirmed in native gallbladder bile as the more physiological effector system.
Wilhelmi
Martin
M
Departments of aMedicine II and bSurgery, Klinikum Grosshadern, Ludwig Maximilians-University Munich, Germany.
Jüngst
Christoph
C
Mock
Melissa
M
Meyer
Günther
G
Zündt
Benedikta
B
Del Pozo
Reginald
R
Jüngst
Dieter
D
D000328:Adult; D000818:Animals; D001646:Bile / Q000737:chemistry* / Q000187:drug effects; D001647:Bile Acids and Salts / Q000032:analysis; D002417:Cattle; D002784:Cholesterol / Q000032:analysis / Q000737:chemistry*; D003460:Crystallization; D005260:Female; D005704:Gallbladder / Q000737:chemistry*; D042882:Gallstones / Q000378:metabolism*; D006801:Humans; D008055:Lipids / Q000032:analysis; D008297:Male; D008875:Middle Aged; D009077:Mucins / Q000008:administration & dosage / Q000032:analysis*; D010743:Phospholipids / Q000032:analysis; D013997:Time Factors
D001647:Bile Acids and Salts; D008055:Lipids; D009077:Mucins; D010743:Phospholipids; D002784:Cholesterol