The Etiology of Gall Stones. I. Chemical Factors. ∗

Abstract

The problem of gall stone formation is the problem of the precipitation of cholesterol out of the bile. An explanation is only-possible when we know how the cholesterol is held in solution in the bile. The bile differs from all the other body fluids in that it contains large amounts of bile salts which, for a long time, have been known to have the power to hold many ordinarily insoluble substances in solution. Long ago Wieland and Sorge 1 showed that desoxycholic acid, a split product of the glyco- and taurodesoxy-cholic acids occurring in bile formed with various substances, insoluble in water, a soluble addition compound. We have investigated the question as to whether one certain bile acid or all bile acids are responsible for the solubility of the cholesterol in the bile.

We have found that when bile acids are precipitated from human gall bladder or fistula bile by FeCl₃, lead acetate by acidification, or by any other means there is a simultaneous precipitation of cholesterol. This can easily be proved by dissolving the bile acid fraction in alcohol and adding digitonin, which brings down a precipitate of cholesterol-digitonid. The complex of bile acids and cholesterol is readily soluble in water and may be purified by various methods without lessening the cholesterol content. These substances have about the same cholesterol content, 6-9%, without regard to the form of bile acids from which they are made.

These same products may be prepared from pure bile acids. We have made these complexes from cholic, desoxycholic acid, glycocholic and taurocholic acids. The properties of these substances are very similar. The bond between the cholesterol and the bile acid is a very loose one and even in the preparation there is very often a slight loss of cholesterol.