Immunocytochemical visualization of DNA adducts in mouse tissues and human white blood cells following treatment with benzo[a]pyrene or its diol epoxide. A quantitative approach.
The formation and stability of benzo[a]pyrene DNA adducts were studied in tissues of BALB/c mice exposed to benzo[a]pyrene (B[a]P). The DNA adducts were visualized with an immunocytochemical peroxidase staining technique using an antiserum specific for the major B[a]P-derived adduct in DNA [(+/-)trans-7,8-dihydroxy-anti-9,10-epoxy-7,8,9,10- tetrahydrobenzo[a]pyrene (BPDE-N2-dG)]. The nuclear staining density was measured by microdensitometry. When mice were treated with an increasing dose of B[a]P the nuclear staining increased in the tissues studied (lung, heart and kidney). A linear relationship was found between the immunocytochemical nuclear staining signal and the actual DNA adduct level in the lung as measured by 32P-postlabeling. Maximum adduct formation was found 5 days after a single i.p. injection of B[a]P. Adduct levels decreased gradually after 7 days, but even after 61 days a slight specific staining was still present, suggesting that not all adducts had disappeared at that time. As judged from the disappearance of [3H]thymidine from prelabeled DNA the loss of adducts from the lung was not a result of DNA repair but one of cell turnover. In human white blood cells B[a]P-derived adducts could be detected after in vitro incubation with the reactive metabolite of B[a]P (BPDE). Dose-response studies demonstrated a positive relationship between BPDE-DNA adduct formation, the immunocytochemical staining signal and the BPDE concentration in the culture medium.
van Schooten
F J
FJ
Division of Chemical Carcinogenesis, The Netherlands Cancer Institute, Amsterdam.
Hillebrand
M J
MJ
Scherer
E
E
den Engelse
L
L
Kriek
E
E
D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide / Q000378:metabolism*; D000818:Animals; D001564:Benzo(a)pyrene / Q000378:metabolism*; D002478:Cells, Cultured; D004247:DNA / Q000378:metabolism*; D018736:DNA Adducts; D003720:Densitometry / Q000379:methods; D004101:Dihydroxydihydrobenzopyrenes / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D007150:Immunohistochemistry; D007668:Kidney / Q000378:metabolism; D007962:Leukocytes / Q000166:cytology / Q000378:metabolism*; D008168:Lung / Q000378:metabolism; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009206:Myocardium / Q000378:metabolism; D010761:Phosphorus Radioisotopes
C057268:7,8-dihydroxy-9,10-oxy-7,8,9,10-tetrahydrobenzo(a)pyrene-DNA adduct; D018736:DNA Adducts; D004101:Dihydroxydihydrobenzopyrenes; D010761:Phosphorus Radioisotopes; C043931:benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide-DNA; C056612:benzo(a)pyrene-DNA adduct; D001564:Benzo(a)pyrene; D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide; D004247:DNA