Composition Difference of Cholesterol-, Pigment- and Mixed-Type Gallstones, and Their Formation Mechanisms

Objective: The chemical compositions and formation mechanisms of different types of gallstones (cholesterol-, pigment-, and mixed-type) were studied. Methods: The components of gallstones were identified by Fourier transform infrared spectroscopy (FT-IR). The contents of cholesterol, bilirubin and bile acid in gallstones were determined by ultraviolet visible (UV-vis) spectrophotometry. Results: The majority of gallstones in Shenzhen area of China were cholesterol stones, followed by pigment stones. The incidence rate of female was significantly higher than that of male; the age of gallstone patients was mainly 30 similar to 50 years old. The pathogenesis of cholesterol gallstone is mainly the supersaturation of cholesterol in the bile. Pigment gallstone is closely related to the formation of calcium bilirubinate complex. Bile pigments can be deposited on cholesterol, then to form calcium bilirubinate, and finally form bile pigment-cholesterol mixed type gallstones. Conclusions: Cholesterol, bilirubin and bile acid play different roles in formation of different types of gallstones. Using UV-vis and FT-IR spectra can accurately detect the components of gallstones, and this analysis can provide inspiration for the effective prevention and treatment of gallstones.