Influence of viability on bromosulfophthalein uptake by isolated hepatocytes

Summary The initial rates of BSP uptake by isolated hepatocytes were compared in cells of good and poor viability. Cells with impaired viability were obtained by ageing or by accident also in fresh preparations. Viability was judged by trypan blue stainability, membrane potential and respiratory parameters indicative for energy state, substrate supply and plasma membrane permeability changes. It was found that concomitant with impaired viability there was a decline of uptake rates at low and an increase at high BSP concentrations with a crossover point at 10 M as manifest in an increase of K_m and V. Simultaneously, the affinity and size of the membrane bound fraction decreases. The results give kinetic support to the supposition that it is the decreased uptake from plasma to liver that is responsible for the prolonged plasma retention times in the liver function test of patients with impaired hepatobiliary function.Abbreviations BSP Bromosulfophthalein - CCP Carbonylcyanide m-chlorophenylhydrazoneA preliminary report was given on the Spring Meeting of the German Pharmacological Society at Mainz, March 23–26, 1976 [Schwenk, M., Burr, R., Pfaff, E.: Naunyn-Schmiedeberg's Arch. Pharmacol. 293, R48 (1976)].This study was supported by the Deutsche Forschungsgemeinschaft. The authors wish to thank Mrs. Sylvia Kasperek for skilful technical assistance.