Cholesterol monohydrate growth in model bile solutions.

The growth of cholesterol monohydrate from solutions of bile salt, lecithin, and small electrolytes has been studied by microscopy and with the Coulter Counter. The crystal forms found by microscopy are the same as those seen in human gallstones and in squirrel monkey cholesterol microliths. The cholesterol growth rates determined with the Coulter Counter vary slowly with cholesterol concentration at low degree of supersaturation but become exponential at higher cholesterol concentrations. Growth is accelerated by the presence of calcium and magnesium but inhibited by potassium. These results can be combined with previous measurements of cholesterol dissolution rates to give a more accurate picture of the dynamics of gallstone formation.