title: Effects on growth and biochemical responses in juvenile gilthead seabream 'Sparus aurata' after long-term dietary exposure to low levels of dioxins.
abstract: The farmed fish gilthead seabream (Sparus aurata) were fed with a dry feed spiked with a low level (23 ng WHO-TEQ/kg of feed) polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) mixture in order to assess bioaccumulation of these contaminants in the muscle and liver tissues after long-term exposure (approximately 390 days). Furthermore, effects on fish growth, feeding and on the response of some biochemical markers (induction of the CYP1A dependent EROD activity, the conjugating enzyme GST, the antioxidant enzymes CAT, t-GPX and DTD, lipid peroxidation and the AhR gene expression) were also evaluated. After feeding with the spiked dry feed for 3 months the PCDD/F concentrations in the exposed fish were 5.50 pg WHO-TEQ/g fresh weight (f.w.) in flesh and 8.45 pg WHO-TEQ/g f.w in liver tissue, which are approximately 24-fold and 14-fold higher than background levels, respectively. However, a progressive increase in PCDD/F levels was not found during the rest of the exposure period. Differences in fish growth were not observed between dioxin-exposed and non-exposed animals and, in addition, no mortalities were recorded attributable to the dioxin intake. Significant increases in the EROD activity, as well as in AhR gene expression were observed in liver after approximately 300 days of exposure. However, no effect on the antioxidant enzymes CAT and t-GPX was found.
authors.affiliation: Laboratory of Dioxins, Mass Spectrometry Laboratory, Department of Ecotechnologies, IIQAB-CSIC, Jordi Girona 18-21, 08034 Barcelona, Spain.
authors.forename: Manuela
authors.initials: M
authors.lastname: Abalos
authors.forename: Esteban
authors.initials: E
authors.lastname: Abad
authors.forename: Alicia
authors.initials: A
authors.lastname: Estévez
authors.forename: Montserrat
authors.initials: M
authors.lastname: Solé
authors.forename: Astrid
authors.initials: A
authors.lastname: Buet
authors.forename: Laia
authors.initials: L
authors.lastname: Quirós
authors.forename: Benjamin
authors.initials: B
authors.lastname: Piña
authors.forename: Josep
authors.initials: J
authors.lastname: Rivera
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D001522:Behavior, Animal / Q000187:drug effects; D001572:Benzofurans / Q000008:administration & dosage / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D015415:Biomarkers / Q000378:metabolism; D049628:Body Size / Q000187:drug effects; D019363:Cytochrome P-450 CYP1A1 / Q000378:metabolism; D000072338:Dibenzofurans, Polychlorinated; D004032:Diet / Q000009:adverse effects*; D004305:Dose-Response Relationship, Drug; D004781:Environmental Exposure; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D005982:Glutathione Transferase / Q000378:metabolism; D008024:Ligands; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000166:cytology / Q000378:metabolism; D009132:Muscles / Q000166:cytology / Q000378:metabolism; D000072317:Polychlorinated Dibenzodioxins / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity; D018336:Receptors, Aryl Hydrocarbon / Q000378:metabolism; D021541:Sea Bream / Q000254:growth & development* / Q000378:metabolism* / Q000502:physiology; D013997:Time Factors
chemical_list: D000975:Antioxidants; D001572:Benzofurans; D015415:Biomarkers; D000072338:Dibenzofurans, Polychlorinated; D008024:Ligands; D000072317:Polychlorinated Dibenzodioxins; D018336:Receptors, Aryl Hydrocarbon; D019363:Cytochrome P-450 CYP1A1; D005982:Glutathione Transferase