Dissolution of Human Cholesterol Gallstones in Simulated Chenodeoxycholate-Rich and Ursodeoxycholate-Rich Biles

We have compared the kinetics and physical-chemical mechanisms of human cholesterol gallstone dissolution in simulated normal, chenodeoxycholaterich, and ursodeoxycholate-rich “biles.” Owing to reduced micellar cholesterol solubilizing capacities, dissolution rates in ursodeoxycholate-rich biles were initially slower than in normal or chenodeoxycholate-rich biles. At later time points, dissolution rates in ursodeoxycholate-rich bile became accelerated; this was shown to be associated with the development of a JameJJar liquid-crystalline phase that took place first on the stones’ surfaces and was then followed by dispersion of liquid-crystalline vesicles into the micellar solution. As subsequent dissolution occurred in a two-phase system of micelles and liquid-crystalline vesicles, the quantity of cholesterol solubilized exceeded micellar saturation. In normal and chenodeoxycholate-rich biles, no phase changes