Determination of sulfobromophthalein excretion in rabbits

The excretion of sulfobromophthalein (BSP) is determined by hepatic uptake (storage capacity) and secretion (transport maximum). We calculated the BSP excretion data in six rabbits by measuring the rate of rise of BSP at various infusion rates. The relative storage capacity was determined to be 0.34 +/- 0.13 mg.mg-1.dl-1.kg-1. The transport maximum was calculated to be 0.91 +/- 0.12 mg.min-1.kg-1. These results compare closely with previously reported results using more direct measurements that require anesthesia and surgical cannulation of the biliary tree. Repeated studies were easily performed. Our method provides a reliable and simple technique to study the effects of various conditions or substances on BSP excretion in conscious, unanesthetized rabbits.