title: Toxicity and modulations of biomarkers in Xenopus laevis embryos exposed to polycyclic aromatic hydrocarbons and their N-heterocyclic derivatives.
abstract: Effects of a newly identified group of organic environmental pollutants of concern (N-heterocyclic derivatives of polycyclic aromatic hydrocarbons, NPAHs) were investigated using the 96 h FETAX (Frog Embryo Teratogenesis Assay - Xenopus). Beside standard FETAX parameters (mortality, malformations), changes in several biochemical markers were studied as early signs of intoxication. Biomarkers included determination of glutathione (GSH) levels and lipid peroxidation as well as activities of important detoxification and antioxidant enzymes (glutathione-S-transferase, glutathione peroxidase, glutathione reductase). 1,10-Phenathroline was the most toxic of all tested compounds (96 h LC(50) = 4 microM). All tested NPAHs induced malformations in the frog embryos. The data suggest that the exposure to NPAHs can induce oxidative stress in amphibians; most biochemical markers were modulated at concentrations lower than those resulting in significant mortality. Results document mortality and teratogenicity of all studied NPAHs to amphibian embryos while no significant mortality, teratogenicity or modulations in biochemical markers could be observed with unsubstituted polycyclic aromatic hydrocarbons (PAHs) at concentrations up to their water solubility. This information along with the significantly greater solubility and thus bioavailability compared to their nonsubstituted parent compounds suggests that NPAHs could contribute significantly to the overall aquatic toxicity of mixtures of PAHs and their derivatives.
authors.affiliation: Research Centre for Environmental Chemistry and Ecotoxicology (RECETOX), Masaryk University, Kamenice 3, CZ 625 00 Brno, Czech Republic. buryskova@recetox.muni.cz
authors.forename: Blanka
authors.initials: B
authors.lastname: Burýsková
authors.forename: Klára
authors.initials: K
authors.lastname: Hilscherová
authors.forename: Ludek
authors.initials: L
authors.lastname: Bláha
authors.forename: Blahoslav
authors.initials: B
authors.lastname: Marsálek
authors.forename: Ivan
authors.initials: I
authors.lastname: Holoubek
mesh_terms: D000014:Abnormalities, Drug-Induced / Q000209:etiology / Q000662:veterinary; D000818:Animals; D015415:Biomarkers / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000002:abnormalities* / Q000378:metabolism; D004785:Environmental Pollutants / Q000737:chemistry / Q000633:toxicity; D005260:Female; D006575:Heterocyclic Compounds, 3-Ring / Q000737:chemistry / Q000633:toxicity; D006801:Humans; D008297:Male; D010616:Phenanthrenes / Q000737:chemistry / Q000633:toxicity; D010618:Phenanthrolines / Q000737:chemistry / Q000633:toxicity; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry / Q000633:toxicity; D018675:Toxicity Tests; D014982:Xenopus laevis / Q000002:abnormalities* / Q000196:embryology / Q000378:metabolism
chemical_list: D015415:Biomarkers; D004785:Environmental Pollutants; D006575:Heterocyclic Compounds, 3-Ring; D010616:Phenanthrenes; D010618:Phenanthrolines; D011084:Polycyclic Aromatic Hydrocarbons