Measurement of drug displacement of protein-bound bilirubin using gel filtration.
Gel filtration was used to measure drug interaction with protein-bound bilirubin in 0.5 ml samples of Gunn rat serum, human serum and fraction V human serum albumin. Using sulfadimethoxine as a prototype differences in displacement were found in all 3 sera. The differences between human and rat serum were related to the binding characteristics of sulfadimethoxine whereas the differences between human serum and fraction V human serum albumin were attributed to displacement of bilirubin from albumin to other proteins in serum. Gel filtration permitted the use of small samples with bilirubin-albumin ratios less than 1.0 and provided data that were used for analysis of drug displacement of bilirubin using principles of drug-receptor theory. Ten of 14 drugs found to alter serum bilirubin concentrations in icteric Gunn rats had measurable effects on protein binding of bilirubin.
D000818:Animals; D001663:Bilirubin / Q000097:blood*; D001665:Binding Sites / Q000187:drug effects; D001667:Binding, Competitive; D001798:Blood Proteins / Q000378:metabolism*; D002850:Chromatography, Gel; D006801:Humans; D066298:In Vitro Techniques; D011485:Protein Binding / Q000187:drug effects; D051381:Rats; D013412:Sulfadimethoxine / Q000097:blood / Q000494:pharmacology*
D001798:Blood Proteins; D013412:Sulfadimethoxine; D001663:Bilirubin