A comparison of the binding and distribution of benzo[a]pyrene in human and rat serum.
Uptake and distribution of benzo[a]pyrene (B[a]P) in human and rat serum were studied by incubation, gel filtration and ultracentrifugation. A maximum uptake of 230 and 120 micrograms B[a]P/ml was found for human and rat serum, respectively. Of the B[a]P uptake about 1% was irreversibly bound to serum constituents from both species. The uptake of B[a]P by the lipoproteins was 90-95% and 80-85% for human and rat serum, respectively, the remainder being bound to albumin. In human serum B[a]P was mainly associated with low density lipoproteins (44-47%) while in rat serum with high density lipoproteins (40-54%). However, the distribution of B[a]P between the different lipoprotein fractions showed a high correlation with the concentration of cholesterol for both species. The present results demonstrate a serum uptake capacity of B[a]P for both species which exceeds any known occupational exposure. The extensive association between B[a]P and lipoproteins may have implications for the availability of B[a]P for metabolizing organs, an area which should be further investigated. As far as the total serum uptake and distribution of B[a]P are concerned, the rat seems to be an acceptable animal model for extrapolation of in vivo results to man.
Aarstad
K
K
Department of Pharmacology and Toxicology, Faculty of Medicine, University of Trondheim, Regional Hospital, Norway.
Toftgård
R
R
Nilsen
O G
OG
D000328:Adult; D000818:Animals; D001564:Benzo(a)pyrene / Q000097:blood*; D006801:Humans; D007700:Kinetics; D008074:Lipoproteins / Q000097:blood* / Q000302:isolation & purification; D008297:Male; D011485:Protein Binding; D051381:Rats; D011919:Rats, Inbred Strains; D013045:Species Specificity
D008074:Lipoproteins; D001564:Benzo(a)pyrene