Biliary excretion of conjugated sulfobromophthalein (BSP) in constitutional conjugated hyperbilirubinemias.

Sulfobromophthalein (BSP) and its three major forms of conjugates were determined in bile or duodenal aspitate, plasma and urine following intravenous administration of free BSP and synthetic BSP-glutathione (BSP-GSH) in five patients with the Dubin-Johnson syndrome and two patients with the Rotor syndrome, using alumina column chromatography. It was found that in Dubin-Johnson patients the biliary excretion of conjugated BSP was selectively impaired, conjugated BSP increased in plasma replacing free BSP after 30 min, and plasma retention of BSP-GSH was greater than that of free BSP when administered intravenously. In contrast, biliary excretion of BSP and its conjugates was not impaired and regurgitation of conjugated BSP into plasma was minimal in the Rotor syndrome. Thus, these two constitutional hyperbilirubinemias can be separated by their basic defects in BSP metabolism.