SPECIES DIFFERENCES IN ALBUMIN BINDING OF 2,4,6-TRINITROBENZALDEHYDE CHLOROPHENOXYACETIC ACIDS 2-(4'-HYDROXYBENZENEAZO)BENZOIC ACID AND SOME OTHER ACIDIC DRUGS - UNIQUE BEHAVIOR OF RAT PLASMA ALBUMIN

Binding of chlorophenoxyacetic acids and other drugs to albumins from different species was studied by equilibrium dialysis and by two optical probes, 2,4,6-trinitrobenzaldehyde (TNBal) and 2-(4′-hydroxybenzeneazo)benzoic acid (HBABA). Rat plasma albumin behaves abnormally, compared with plasma albumin fraction V preparations from ten other species, in its interaction with HBABA in the presence of certain drugs (thyroxine, indolacetates and chlorophenoxy acids). HBABA may be a useful tool for determining the binding of anionic drugs to various albumins (other than pig and horse albumins). No relationship was discovered between albumin binding and hypocholesterolemic activity in vivo in a series of phenoxyacetic acids related to clofibrate (Atromid-S). © 1969.