Dietary production and dissolution of cholesterol gallstones in the mouse.

Groups of animals fed lithogenic diets were sacrificed at intervals, with serum and bladder bile obtained. Bile was analyzed for bile acids, lecithin, free fatty acids, and cholesterol concentrations, serum for cholesterol and free fatty acids. Gall bladders were also examined for histological change. The chemical response to the diets was a prompt increment in serum and bile cholesterol concentrations. After an initial rise, bile acid content of bile decreased, resulting in a fall in bile acid-to-cholesterol ratios to the point of cholesterol precipitation. Stones once formed dissolved when animals harboring stones were fed Purina laboratory chow. Histological changes appeared in the gall bladder after 2 weeks on the diets and were progressive.