Tissue Distribution of Bile Acids: Methodology and Quantification

Abstract

The observation of Chaikoff’s group (1,2) has been cited as evidence that liver is the only site for cholesterol catabolism to bile acids (3,4). Incubation of various tissue slices of rat liver, kidney, testes, spleen, lung and brain, and beef adrenal, however, resulted in conversion of [26-14C]cholesterol to 14CO2, but [4-14C]cholesterol was not oxidized (3). Since liver was found to be much more active than the other tissues, it was concluded that liver was the major site of bile acid synthesis. Harold et al. (2) concluded the same from a rat liver perfusion study. Liver has been verified as a major site of bile acid synthesis (5,6) but no direct study has ever been reported to verify the incapability of extrahepatic tissues to transform cholesterol to bile acids.