title: Dose-response relationship, kinetics of formation, and persistence of S-[2-(N7-guanyl)-ethyl]glutathione-DNA adduct in livers of channel catfish (Ictalurus punctatus) exposed in vivo to ethylene dichloride.
abstract: Formation of DNA adducts by reactive chemicals or their metabolites are often a precursor of mutagenesis and other adverse effects. Studies in juvenile channel catfish (Ictalurus punctatus) were conducted to determine the dose-response, kinetics of formation, and persistence of S-[2-(N7-guanyl)ethyl]glutathione hepatic-DNA adducts following a 4-h in vivo aqueous exposure to ethylene dichloride (EDC) at several dose levels. S-[2-(N7-guanyl)ethyl] glutathione adducts were detectable in liver tissue after 2 h of exposure and were still detectable three weeks after a single pulse exposure (detection limit=approximately 10 fmol, approximately 1 DNA adduct in 10(7) bases). Pretreatment of catfish with the glutathione-depleting agent diethylmaleate significantly reduced the level of tissue glutathione levels and, as a result, DNA adducts were not detected in pretreated fish. Catfish may serve as a useful sentinel species for detecting DNA-reactive chemicals in aquatic systems.
authors.affiliation: Department of Epidemiology and Surveillance Research, American Cancer Society, Atlanta, Georgia 30329, USA.
authors.forename: Ahmedin
authors.initials: A
authors.lastname: Jemal
authors.forename: Steven A
authors.initials: SA
authors.lastname: Barker
authors.forename: Jay C
authors.initials: JC
authors.lastname: Means
mesh_terms: D000818:Animals; D002273:Carcinogens / Q000493:pharmacokinetics / Q000633:toxicity*; D018736:DNA Adducts / Q000493:pharmacokinetics*; D004305:Dose-Response Relationship, Drug; D008401:Gas Chromatography-Mass Spectrometry; D005978:Glutathione / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000633:toxicity; D007059:Ictaluridae / Q000378:metabolism*; D057230:Limit of Detection; D008099:Liver / Q000187:drug effects* / Q000378:metabolism
chemical_list: D002273:Carcinogens; D018736:DNA Adducts; D005978:Glutathione