title: Neuroendocrine and Eosinophilic Granule Cells in the Gills of Tilapia, Oreochromis niloticus: Effects of Waterborne Copper Exposure.
abstract: The contamination of aquatic ecosystems with copper (Cu) poses a serious threat to aquatic organisms. Although the histopathological changes caused by Cu in fish gills are well documented, knowledge about the impact of this metal in gill specific cell types, such as neuroendocrine cells (NECs) and eosinophilic granule cells (EGCs), is still limited. In the present work, Nile tilapia (Oreochromis niloticus) were exposed for 21 days to nominal concentrations of Cu (40 and 400 µg L(-1)). Stereological methods were used to estimate the volumetric density of both NECs and EGCs in fish gill filament after 3, 7, 14, and 21 days of exposure. The results showed that Cu significantly increased the relative volume of NECs, whereas the relative volume of EGCs decreased. NECs were more affected by Cu in the first 7 days of exposure, during which a greater increase in their relative volume was observed. The Cu exposure induced a progressive decrease in the relative volume of EGCs, which reached statistical significance after 14 days of exposure. An exception was observed in subepithelial EGCs with a slight increase in their relative volume after 3 days of exposure. Our findings confirm that Cu can modulate both neuroendocrine and immune systems and becomes immunotoxic after a prolonged exposure.
authors.affiliation: Department of Biology and Environment, Life Sciences and Environment School, University of Trás-os-Montes and Alto Douro (UTAD), Quinta de Prados, 5000-801, Vila Real, Portugal.
authors.forename: Dércia
authors.initials: D
authors.lastname: Santos
authors.affiliation: Department of Biology and Environment, Life Sciences and Environment School, University of Trás-os-Montes and Alto Douro (UTAD), Quinta de Prados, 5000-801, Vila Real, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Falcão
authors.affiliation: Department of Biology and Environment, Life Sciences and Environment School, University of Trás-os-Montes and Alto Douro (UTAD), Quinta de Prados, 5000-801, Vila Real, Portugal.|Centre for the Research and Technology of Agro-Environmental and Biological Sciences, University of Trás-os-Montes and Alto Douro, Quinta de Prados, 5000-801, Vila Real, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Luzio
authors.affiliation: Department of Biology and Environment, Life Sciences and Environment School, University of Trás-os-Montes and Alto Douro (UTAD), Quinta de Prados, 5000-801, Vila Real, Portugal.|Centre for the Research and Technology of Agro-Environmental and Biological Sciences, University of Trás-os-Montes and Alto Douro, Quinta de Prados, 5000-801, Vila Real, Portugal.
authors.forename: António
authors.initials: A
authors.lastname: Fontaínhas-Fernandes
authors.affiliation: Department of Biology and Environment, Life Sciences and Environment School, University of Trás-os-Montes and Alto Douro (UTAD), Quinta de Prados, 5000-801, Vila Real, Portugal. smonteir@utad.pt.|Centre for the Research and Technology of Agro-Environmental and Biological Sciences, University of Trás-os-Montes and Alto Douro, Quinta de Prados, 5000-801, Vila Real, Portugal. smonteir@utad.pt.
authors.forename: Sandra Mariza
authors.initials: SM
authors.lastname: Monteiro
mesh_terms: D000818:Animals; D023681:Cichlids / Q000502:physiology*; D003300:Copper / Q000633:toxicity*; D004804:Eosinophils; D005880:Gills / Q000166:cytology* / Q000187:drug effects; D055099:Neuroendocrine Cells; D017210:Tilapia / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical; D003300:Copper