Metabolism of Sulfobromophthalein Sodium (BSP) in the Rat

Abstract

Chromatographic analysis of crystalline BSP used for clinical test of liver function showed the BSP to be chromatographically homogeneous. Chromatographic analysis of BSP excreted into bile of the rat showed the excreted BSP to be composed of three similarly colored, but distinct compounds. The compound which had the same chromatographic mobility as the BSP injected amounted to only 9.6% of the BSP injected. The distribution of the compounds derived from BSP showed a continuous change during the course of excretion, but the average distribution for a 40-minute collection period after injection of the BSP was the same for several rats. Metabolic changes of BSP were found among several animal species, and the chromatographic mobilities and distribution of the compounds showed species differences. Spectrophotometric absorption curves of BSP and compounds derived from BSP in the rat were found to overlie exactly, but the derived compounds showed changes in molecular extinction coefficients. One of the derived compounds had the same bromine content as BSP. Incubation of the derived compounds with ß-glucuronidase did not regenerate BSP.