Bile Acid Metabolism in Mammals. III. Sex Difference in the Bile Acid Composition of Rat Bile

Abstract

Bile was collected from 12 rats, six of each sex, for the first 5 h following the creation of a biliary fistula. The bile acid content of the bile was analyzed by combined thin-layer and gas chromatographic techniques. Total bile acids and the glycine and taurine conjugates were measured. Although bile volumes and total bile acid outputs were similar in rats of both sexes, significant sex differences were found in the amounts of individual bile acids secreted. The female rat secretes considerably more cholic and lithocholic acids, and considerably less β-muricholic, deoxycholic, and hyodeoxycholic acids. The female rat also secretes less glycine-conjugated bile acids and in contrast to the male the bulk of this is glycocholic acid. The greater secretion of β-muricholic acid by the male rat suggests that this sex has a more efficient mechanism for the metabolism of chenodeoxycholic acid.