Intestinal absorption and metabolism of norcholic acid in rats

Intestinal absorption and hepatic and intestinal bacterial biotransformations of norcholic acid, the C23 homologue of cholic acid, were studied in the rats. Norcholic acid, like cholic acid, was efficiently absorbed from the intestine and quickly secreted into the bile. Unlike the C24 bile acid, however, which is secreted by rat liver as its taurine conjugate, the C23 bile acid appeared in the bile predominantly as the unconjugated form. conjugated form. Bacterial modification of norcholic acid was similar to but less extensive than that of cholic acid. A considerable part of norcholic acid was left unchanged during its passage through the intestinal tract. A major bacterial metabolite of norcholic acid was the 7-dehydrogenation product, 7-ketonordeoxycholic acid, rather than the 7-dehydroxylation product, nordeoxycholic acid, though the reverse is true for cholic acid.