INTERACTION OF PLASMA AND TISSUE PROTEIN BINDING OF PROMAZINE STUDIED ON ISOLATED PERFUSED RAT LIVER

The uptake of promazine by the isolated rat liver was determined in relation to the protein binding of this drug in the perfusion medium. The perfusion medium contained 1.3×10-4 M promazine and 1%, 2%, 4% or 0% bovine serum albumin and was adjusted to pH 7.4. In the perfusion media containing 1%, 2% or 4% albumin the proportion of promazine not bound to albumin was 51%, 32% and 21% resp. of the total amount. The uptake of promazine into the liver increased with the concentration of free promazine in the perfusion medium. A dynamic equilibrium between the fraction of drug bound to albumin and the fraction bound to tissue was demonstrated. © 1969 Springer-Verlag.