title: Preferential binding of polycyclic hydrocarbons to matrix-bound DNA in rat-liver nuclei.
abstract: The reactions of benzo[a]pyrene and 7,12-dimethylbenz[a]anthracene metabolites and of r-7,t-8-dihydroxy-t-9,10-oxy-7,8,9,10-tetrahydrobenzo[a]pyrene with the DNA of matrix-bound and released chromatin fractions of rat-liver nuclei have been examined. Qualitatively there were no differences between the DNA-bound metabolites in each fraction but more binding to matrix-bound DNA occurred. Evidence was obtained that the increased binding of hydrocarbon to matrix-bound DNA was not dependent upon the proximity of hydrocarbon-metabolizing enzymes and Sephadex LH20 chromatography showed that the differences between the fractions were not due to contamination of DNA with residual proteins. The conformation of the matrix-bound chromatin may make its DNA more accessible to reactive metabolites than that of released chromatin.
mesh_terms: D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide; D015127:9,10-Dimethyl-1,2-benzanthracene / Q000378:metabolism*; D000818:Animals; D001551:Benz(a)Anthracenes / Q000378:metabolism*; D001564:Benzo(a)pyrene; D001580:Benzopyrenes / Q000378:metabolism*; D002273:Carcinogens / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism; D004247:DNA / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D001551:Benz(a)Anthracenes; D001580:Benzopyrenes; D002273:Carcinogens; D002843:Chromatin; D001564:Benzo(a)pyrene; D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide; D015127:9,10-Dimethyl-1,2-benzanthracene; D004247:DNA