Abstract
Both stagnation and infection of bile, especially with Escherichia coli, together with dietary deficiencies, seem to induce formation of calcium bilirubinate stones. As to the mechanism by which calcium bilirubinate is separated out of bile, the activity of β-glucuronidase of bacterial origin is presumed to play an essential role; the enzyme hydrolyzes bilirubin glucuronide into free bilirubin and glucuronic acid, and calcium in bile combines at the carboxyl radical of free bilirubin to form calcium bilirubinate. On the other hand, bile usually has an inhibitory effect on β-glucuronidase activity. This is mainly due to glucaro-1, 4-lactone (glucaric acid) which is present in bile and known to be the most powerful inhibitor of β-glucuronidase.
