The effect of bilirubin on biliary iodipamide excretion in the dog

The effect of bilirubin on biliary iodipamide excretion and concentration was investigated in cholecystectomized dogs during complete bile diversion and constant bile salt replacement. A significant dose-dependent depression of both biliary iodipamide excretion rate and bile iodipamide concentration was found with increasing bilirubin dose. Whether or not bilirubin was infused at a constant of 0.1 mu moles/min/kg, the excretion rate and bile concentration of iodipamide was greatest with the largest 5.2 mu moles/min/kg iodipamide dose. Iodipamide had no significant effect on the bilirubin excretion rate, but because of its highly choleretic nature it had a dilution effect on the bilirubin bile concentration. This investigation suggests that a reduction of the iodipamide blood levels by either decreasing the dose or prolonging the infusion time will lead to poorer radiographic visualization of the biliary system in patients with unconjugated hyperbilirubinemia (prehepatic jaundice).