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

Authors

  • Ahmedin Jemal,

    1. Department of Epidemiology and Surveillance Research, American Cancer Society, Atlanta, Georgia 30329, USA
    2. Department of Epidemiology and Community Health, School of Veterinary Medicine, Louisiana State University Baton Rouge, Louisiana 70803, USA
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  • Steven A. Barker,

    1. Department of Veterinary Physiology, School of Veterinary Medicine, Louisiana State University Baton Rouge, Louisiana 70803, USA
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  • Jay C. Means

    Corresponding author
    1. Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois 62901, USA
    • Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois 62901, USA.
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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 (Ictaluruspunctatus) 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 = ∼10 fmol, ∼1 DNA adduct in 107 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. Environ. Toxicol. Chem. 2010;29:1537–1544. © 2010 SETAC

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