Impaired Biliary Excretion of Phenol 3, 6-Dibromphthalein Disulfonate in Neonatal Guinea Pigs

Hepatic disposition of DiBSP was studied in adult and newborn guinea pigs from days 2 through 16 of life after intravenous administration of DiBSP in doses sufficient to achieve maximal rates of dye excretion into bile. Neonatal guinea pigs showed a significant reduction in the maximal rate of dye excretion into bile when compared to adult animals. A minimal estimate of hepatic uptake of DiBSP showed that uptake was similar in neonatal and adult animals and was significantly greater than the maximal rates of excretion into bile. Hence hepatic uptake did not limit hepatic disposition of DiBSP. With aging, injected DiBSP was excreted at progressively more rapid rates reaching adult levels of excretion at the beginning of the second week of life. This study demonstrates the presence of a defect in the excretory process by which DiBSP is transported from liver cells into bile in the neonatal guinea pig.