Animal Models of Calcium Cholelithiasis

Abstract

Bile contains four calcium anions which are readily precipitated by calcium: bilirubinate, “palmitate”, carbonate and phosphate. Precipitation of insoluble calcium salts is common in calculous biliary disease. All animal models of calcium cholelithiasis probably share a common pathogenesis‐an increased concentration of a calcium‐sensitive anion. In calcium bilirubinate cholelithiasis, an increased concentration of bilirubinate occurs. In mice, this occurs in animals having a genetic hemolytic anemia; in rats, it may be induced by an essential fatty acid in combination with diet modification; in dogs, by a low‐taurine, low‐protein diet; and in prairie dogs, by ileal resection which probably increases the bilirubinate/bile acid ratio in bile. In the two models of calcium‐bile acid cholelithiasis, an increased biliary concentration of a calcium‐sensitive glycine conjugated bile acid is induced by administration of a suitable precursor. In the rabbit, gallstones composed mostly of calcium allodeoxycholyl glycine are induced by the feeding of 5β‐cholestan‐3β‐ol. In the taurine‐deficient rat, the feeding of lithocholate leads to formation of gallstones which contain a mixture of calcium lithocholyl glycine and 3α,6β‐dihydroxy cholanoyl glycine. These animal models may be of value in testing agents designed to lower calcium activity in bile. Copyright © 1984 American Association for the Study of Liver Diseases