1. In order to investigate the effect of extra-hepatic biliary obstruction on bilirubin transport, bile flow was re-established after 5, 10, 15 and 28 days when the mean (±sem) plasma bilirubin concentrations of the four groups of five rats were 226 ± 17.9, 201 ± 22.4, 178 ± 8.1 and 145 ± 3.8 μmol/l, respectively.
2. After 12 h of bile drainage in the conscious animal, the mean plasma bilirubin concentrations of the four groups had decreased by 88, 86, 73 and 46%, respectively.
3. The bile flow rate increased with the duration of the obstruction and was maximal in the 28 day obstructed rats, although the bilirubin output in these animals was significantly less than in the other groups.
4. Histological evidence of biliary obstruction was apparent in the livers of the 5 and 10 day obstructed animals. After 15 days of obstruction cirrhosis developed.
5. In conclusion, the disposal of endogenous bilirubin in the bile duct obstructed rat appears to be influenced by the development of cirrhosis.