Transition metals are preferentially precipitated in the cores of solitary cholesterol gallstones

Cholesterol gallstones contain precipitated calcium salts and proteins which are often concentrated in stone centers. Up to 15% of patients with cholesterol gallstones possess a large solitary gallstone. Biliary transferrin, a potent pronucleator of cholesterol crystals, binds a variety of transition metals such as Fe, Cu and Zn. The purpose of this study was to compare the relative concentrations of Ca, Fe, Cu and Zn in the centers and peripheries of solitary and multiple gallstones. Therefore, solitary (S, n=13) and multiple (M, n=15) cholesterol stones were collected, washed, dried and stored at room temperature. Representative areas from each core and periphery were dissected. Powdered samples were subjected to acid digestion and prepared for quantitative elemental analysis by inductively coupled plasma analysis (ICP). Ca, Fe, Cu, and Zn concentrations from the core and periphery in each stone type were