Nucleation time and fatty acid composition of lecithin in human gallbladder bile.

We investigated the relationship between bile nucleation time and the fatty acid composition of biliary lecithin in human gallbladder bile. Bile samples from patients with cholesterol gallstones nucleated more rapidly than those from patients with noncholesterol gallstones or no stones. The biliary cholesterol concentration was highest in the cholesterol gallstone group and was correlated with the molar percentage of linoleic acid and arachidonic acid, with these percentages also being higher in bile from the cholesterol gallstone patients than in bile from the other two groups. In addition, the mucous glycoprotein concentration in bile was also significantly higher in the cholesterol gallstone group. Thirty-three patients in the no-stone group showed bile nucleation times of less than 21 days. Higher concentrations of cholesterol and mucous glycoprotein and higher molar percentages of arachidonic and linoleic acid were noted in these patients. These findings suggest that in humans, hepatic cholesterol hypersecretion is associated with the increased unsaturated fatty acid proportion in biliary phospholipids and gallbladder mucin hypersecretion, thereby causing rapid cholesterol crystal nucleation.