Binding of Sulfobromophthalein Sodium (BSP) and Other Organic Anions By Isolated Hepatic Cell Plasma Membranes in vitro.

Isolated, hepatic cell plasma membranes bound on average 160 ± 2 μg of sulfobromophthalein (BSP) per mg of protein. Taurocholate, bilirubin and fluore-scein, which do not compete for hepatic uptake with BSP when simultaneously injected in vivo, exhibited little or no interference with BSP binding by hepatic cell plasma membranes in vitro. Other organic anions, such as indocyanine green, flavaspidic acid glucaminate, and iodipamide methylgluca-mine, which compete with BSP for hepatic uptake in vivo, significantly reduced BSP binding by isolated membranes in vitro.