Immunohistochemical detection of 1,N(6)-ethenodeoxyadenosine, a promutagenic DNA adduct, in liver of rats exposed to vinyl chloride or an iron overload.
Etheno adducts in DNA bases are formed from exogenous agents such as vinyl chloride and urethane, but also via endogenous lipid peroxidation products like trans-4-hydroxy-2-nonenal. An immunohistochemical method was developed to localize the promutagenic 1,N(6)-ethenodeoxyadenosine DNA adduct in liver of rats exposed to vinyl chloride or an iron overload with or without carbon tetrachloride. Six monoclonal antibodies, previously produced through collaborative efforts, were screened for their optimal adduct recognition and low background formation. The antibody generated by clone EM-A-4 was found to be most suitable. Semi-quantitative image analysis of relative pixel intensity showed approximately 1.5 times higher adduct levels (P < 0.05) in the livers of rats treated with vinyl chloride or an iron overload when compared with untreated controls. Significantly elevated adduct levels persisted in vinyl chloride-treated rat liver 14 days after cessation of exposure, suggesting that this adduct is not rapidly eliminated from rat liver DNA. Using the new immunohistochemical method it is possible to visualize this promutagenic etheno-DNA adduct that may play a role in oxidative stress and lipid peroxidation-induced DNA damage in carcinogenesis.
Yang
Y
Y
Division of Toxicology and Cancer Risk Factors, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany.
Nair
J
J
Barbin
A
A
Bartsch
H
H
D000818:Animals; D018736:DNA Adducts / Q000032:analysis*; D003839:Deoxyadenosines / Q000032:analysis*; D005260:Female; D016158:Genes, p53; D007150:Immunohistochemistry; D019190:Iron Overload / Q000378:metabolism*; D009153:Mutagens / Q000032:analysis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014752:Vinyl Chloride / Q000378:metabolism*
D018736:DNA Adducts; D003839:Deoxyadenosines; D009153:Mutagens; C032221:1,N(6)-ethenodeoxyadenosine; D014752:Vinyl Chloride