Chemical Changes in Infected Dogs' Gall Bladder Bile. ∗

Abstract

Previous experiments 1 have been reported showing that bile salts are absorbed faster than cholesterol from the infected dog's gall bladder. The importance of this lies in the fact that it is the bile salts that hold the cholesterol in solution and if the ratio falls below a certain critical level, cholesterol will be precipitated out of the bile. In former experiments the cystic ducts were closed so that no more bile could enter the gall bladder. In the experiments here reported the ducts were not ligated so that it was possible for bile continually to pour into the gall bladder and further concentration of cholesterol to occur, while the bile salts are progressively absorbed.

Streptococci and filtered emulsions of dog feces were used, the latter instead of pure cultures as they represent a better cross section of the intestinal flora. The injections were made by needle puncture and by insertion of a ureteral catheter up the common duct into the gall bladder. In the latter cases the common duct was ligated at the site of injection. The accompanying table shows that the bile salt content was reduced on the average to about 25% of normal figures while the cholesterol content was approximately doubled.

In vitro control experiments show that no such changes are effected by the action of bacteria on bile.

That this rise in the cholesterol content is not due to secretion of cholesterol by the gall bladder wall is shown by the previously reported series of 57 experiments in which closed infected gall bladders showed no increase in the cholesterol content.

Conclusion. The infected gall bladder of the dog absorbs bile salts and continues to concentrate cholesterol to levels at which it can no longer be held in solution by the bile salts.