title: Chronic Effects of Realistic Concentrations of Non-essential and Essential Metals (Lead and Zinc) on Oxidative Stress Biomarkers of the Mosquitofish, Gambusia holbrooki.
abstract: Metallic contamination is widespread, particularly in areas impacted by human activities. Human activities result in high loads of metals being discarded into the aquatic compartment, reinforcing the need to evaluate their toxic effects especially on exposed fish. The purpose of this study was to determine the toxic response (namely, antioxidant levels and lipoperoxidative damage) in both liver and gills of the freshwater fish species Gambusia holbrooki, exposed to lead and zinc. Fish were exposed for 28 days (chronic exposure) to ecologically relevant concentrations of the selected compounds. The following oxidative stress/damage biomarkers were evaluated: glutathione-S-transferases (GSTs), glutathione reductase (GR), and thiobarbituric acid reactive substances (TBARS). The results indicate that lead caused a significant oxidative response, with significant increase of the enzymatic antioxidant defense (GSTs activity in hepatic tissue, and GR activity in branchial tissue) of exposed organisms. On the other hand, zinc caused a significant inhibition of G. holbrooki hepatic GR, a biological response that may be related to the antioxidant activity exhibited by this metal. The obtained results are of high importance, especially if one considers that the obtained toxic responses occurred at low, albeit ecologically relevant, levels of exposure.
authors.affiliation: Departamento de Biologia, Centro de Estudos do Ambiente e do Mar (CESAM), Universidade de Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal. nunes.b@ua.pt.
authors.forename: Bruno
authors.initials: B
authors.lastname: Nunes
authors.affiliation: Departamento de Biologia, Centro de Estudos do Ambiente e do Mar (CESAM), Universidade de Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.
authors.forename: Carina
authors.initials: C
authors.lastname: Caldeira
authors.affiliation: Departamento de Biologia, Centro de Estudos do Ambiente e do Mar (CESAM), Universidade de Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.
authors.forename: Joana
authors.initials: J
authors.lastname: Luísa Pereira
authors.affiliation: Departamento de Biologia, Centro de Estudos do Ambiente e do Mar (CESAM), Universidade de Aveiro, Campus Universitário de Santiago, 3810-193, Aveiro, Portugal.
authors.forename: Fernando
authors.initials: F
authors.lastname: Gonçalves
authors.affiliation: Centro Interdisciplinar de Investigação Marinha e Ambiental (CIIMAR/CIMAR), Rua dos Bragas 289, 4050-123, Porto, Portugal.|Faculdade de Ciências da Saúde da Universidade Fernando Pessoa (FCS-UFP), Rua Carlos da Maia 296, 4200-150, Porto, Portugal.
authors.forename: Alberto Teodorico
authors.initials: AT
authors.lastname: Correia
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D003532:Cyprinodontiformes / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D007854:Lead / Q000633:toxicity*; D008099:Liver / Q000378:metabolism; D018384:Oxidative Stress / Q000502:physiology; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D036401:Toxicity Tests, Chronic; D014874:Water Pollutants, Chemical / Q000633:toxicity*; D015032:Zinc / Q000633:toxicity*
chemical_list: D015415:Biomarkers; D017392:Thiobarbituric Acid Reactive Substances; D014874:Water Pollutants, Chemical; D007854:Lead; D005980:Glutathione Reductase; D005982:Glutathione Transferase; D015032:Zinc