Red cell destruction and bilirubin production in adult rats with short-term biliary obstruction

The rate of total bilirubin production and the concomitant relative rate of early-labeled bilirubin (ELB) formation were studied in adult Wistar rats with short-term common bile duct ligation. The pulmonary excretion rate of CO (VeCO), an index of total bilirubin production, was measured preoperatively and postoperatively on day 3 and on day 5 or 6. While the VeCO measurements of control and experimental animals were similar preoperatively, the postoperative VeCO measurements of the experimental animals averaged 30% higher than those of control animals. On postoperative day 3, the relative rate of ELB formation was measured by the recovery of excreted 14CO after the administration of 14C-labeled delta-aminolevulinic acid (ALA) or glycine as nonerythropoietic or total heme synthesis precursor, respectively. No significant differences were found in the 14CO recovered from either compound during the study period between the experimental and control animals. The half-life of 51Cr-labeled transfused red blood cells was decreased by nearly 50% in bile duct ligated rats compared to that in the sham operated ones. We conclude that hemolysis is a major factor contributing to the increase in total bilirubin production even after short-term biliary obstruction in the rat.