Hydroxylation of secondary bile acids in the perfused prairie dog liver.

Taurolithocholic acid and deoxycholic acid were perfused into isolated prairie dog livers. Taurolithocholic acid was 7 alpha-hydroxylated to form taurochenodeoxycholic acid, whereas deoxycholic acid was conjugated and 7 alpha-hydroxylated to form taurocholic acid. The low concentrations of secondary bile acids observed in prairie dog bile are due, at least in part, to active bile acid 7 alpha-hydroxylase(s) in the liver of these animals.