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Biochemical and molecular biomarkers in integument biopsies of free-ranging coastal bottlenose dolphins from southern Brazil

Righetti, Barbara Pacheco Harrison, Mattos, Jacó Joaquim, Siebert, Marília Nardelli, Daura-Jorge, Fábio Gonçalves, Bezamat, Carolina, Fruet, Pedro Friedrich, Genoves, Rodrigo Cezar, Taniguchi, Satie, da Silva, Josilene, Montone, Rosalinda Carmela, Simões-Lopes, Paulo César de Azevedo, Bainy, Afonso Celso Dias, Lüchmann, Karim Hahn
Chemosphere 2019 v.225 pp. 139-149
Tursiops truncatus, adverse effects, animals, biomarkers, biopsy, blubber, cytochrome P-450, estuaries, glutathione peroxidase, glutathione transferase, glutathione-disulfide reductase, integument, interleukin-1alpha, linear models, major histocompatibility complex, messenger RNA, metallothionein, persistent organic pollutants, pesticides, polybrominated diphenyl ethers, polychlorinated biphenyls, risk, summer, superoxide dismutase, wildlife, winter, Brazil
Adverse effects of exposure to persistent organic pollutants (POPs) threaten the maintenance of odontocete populations. In southern Brazil, coastal bottlenose dolphins from the Laguna Estuarine System (LES) and Patos Lagoon Estuary (PLE) were sampled using remote biopsies during the winter and summer months. Levels of bioaccumulated POPs were measured in the blubber. The activities of glutathione S-transferase (GST), glutathione reductase (GR), glutathione peroxidase (GPx), and superoxide dismutase (SOD) were also quantified, as were the mRNA transcript levels of aryl hydrocarbon receptor (AhR), AhR nuclear translocator (ARNT), cytochrome P450 1A1-like (CYP1A1), metallothionein 2A (MT2A), GST-π, GPx-4, GR, interleukin 1 alpha (IL-1α), and major histocompatibility complex II (MHCII) in the skin. In general, levels of POPs were similar among sites, sexes, ages and seasons. For most animals, total polychlorinated biphenyl (ΣPCBs) levels were above the threshold level have physiological effects and pose risks to cetaceans. The best-fitting generalized linear models (GLMs) found significant associations between GR, IL-1α and GPx-4 transcript levels, SOD and GST activities, and total polybrominated diphenyl ether (ΣPBDEs) and pesticide levels. GLMs and Kruskal-Wallis analyses also indicated that there were higher transcript levels for most genes and lower GST activity in the winter. These results reinforce the need to consider the influence of environmental traits on biomarker values in wildlife assessments.