Formation of DNA adducts and induction of mutations in rats treated with tumorigenic doses of 1,6-dinitropyrene.
1,6-Dinitropyrene, a component of diesel exhaust, is a lung carcinogen in male F344 rats following a single intrapulmonary administration. In this study, rats were treated with tumorigenic doses of 1,6-dinitropyrene to establish dose-response relationships for the formation of DNA adducts in target (lung) and nontarget (liver) tissues and for the induction of 6-thioguanine-resistant mutations in spleen T-lymphocytes. One week after treatment with 0.3, 1, 3, 10, 30, 100, or 150 micrograms of 1,6-dinitropyrene, dose-responsive DNA binding was measured in lung and liver with binding in the lung being 10-fold higher than in the liver. In the lung, a 2-fold increase in dose resulted in a 1.8-fold increase in DNA binding at treatments up to 30 micrograms of 1,6-dinitropyrene, while in the liver, a 2-fold increase in 1,6-dinitropyrene produced a 2-fold increase in DNA binding at doses up to the 10 micrograms treatment. Higher doses of 1,6-dinitropyrene resulted in proportionally smaller increases in adduct formation in the two tissues. When measured 21 weeks after treatment, mutations in T-lymphocytes increased with doses up to 100 micrograms of 1,6-dinitropyrene, but the response was nonlinear throughout the dose range. These findings indicate that concentrations of 1,6-dinitropyrene that produce a dose-dependent induction of lung tumors also result in a dose-dependent formation of DNA adducts and induction of lymphocyte mutations but that the dose-response curves for DNA binding and mutations are different.
Beland
F A
FA
Division of Biochemical Toxicology, National Center for Toxicological Research, Jefferson, AR 72079-9502.
Fullerton
N F
NF
Smith
B A
BA
Heflich
R H
RH
D000818:Animals; D002273:Carcinogens / Q000633:toxicity*; D004247:DNA / Q000378:metabolism; D018736:DNA Adducts / Q000096:biosynthesis*; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008168:Lung / Q000187:drug effects / Q000378:metabolism; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism; D008297:Male; D009153:Mutagens / Q000633:toxicity*; D011721:Pyrenes / Q000633:toxicity*; D051381:Rats; D011916:Rats, Inbred F344; D013154:Spleen / Q000187:drug effects / Q000378:metabolism
D002273:Carcinogens; D018736:DNA Adducts; D009153:Mutagens; D011721:Pyrenes; C033309:1,6-dinitropyrene; D004247:DNA