Comparison of biliary excretory function and bile composition in male, female, and lactating female rats.

The rates of excretion of phenol-3,6-dibromphthalein disulfonate, ouabain, indocyanine green, and amaranth into the bile of male and female rats were found to be similar. The rates of bile production in male and female rats were also similar whereas that of lactating rats was 50% greater. The increase in bile production occurred during pregnancy and decreased rapidly after removal of the pups from the dam. The increased bile production was of canalicular origin and was due to an increase in both the bile salt-dependent and independent fractions. The lactating rats tended to excrete some xenobiotics more rapidly than did the other rats, but no difference in the biliary excretion was observed in male and female rats.