Effects on growth and biochemical responses in juvenile gilthead seabream ‘Sparus aurata’ after long-term dietary exposure to low levels of dioxins

• Published in: Chemosphere (Oxford) Vol. 73; no. 1; pp. S303 - S310
• Main Authors: Ábalos, Manuela, Abad, Esteban, Estévez, Alicia, Solé, Montserrat, Buet, Astrid, Quirós, Laia, Piña, Benjamin, Rivera, Josep
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.08.2008
• Subjects: AhR gene; animal growth; Animals; antioxidant activity; Antioxidants - metabolism; Behavior, Animal - drug effects; Benzofurans - administration & dosage; Benzofurans - chemistry; Benzofurans - metabolism; Benzofurans - toxicity; bioaccumulation; Biomarkers; Biomarkers - metabolism; Body Size - drug effects; catalase; Cytochrome P-450 CYP1A1 - metabolism; Dibenzofurans, Polychlorinated; Diet - adverse effects; Dietary bioaccumulation; dioxins; Dose-Response Relationship, Drug; Environmental Exposure; enzymes; EROD activity; farmed fish; feed contamination; feed intake; feeds; fish feeding; Gene Expression Regulation, Developmental - drug effects; glutathione peroxidase; glutathione transferase; Glutathione Transferase - metabolism; Ligands; lipid peroxidation; Lipid Peroxidation - drug effects; Liver - cytology; Liver - metabolism; Muscles - cytology; Muscles - metabolism; PCDD/Fs; polychlorinated dibenzodioxins; Polychlorinated Dibenzodioxins - administration & dosage; Polychlorinated Dibenzodioxins - analogs & derivatives; Polychlorinated Dibenzodioxins - chemistry; Polychlorinated Dibenzodioxins - metabolism; Polychlorinated Dibenzodioxins - toxicity; polychlorinated dibenzofurans; Receptors, Aryl Hydrocarbon - metabolism; Sea Bream - growth & development; Sea Bream - metabolism; Sea Bream - physiology; Sparus aurata; Spiked feed; Time Factors; toxicity; Biomarkers; Spiked feed; EROD activity; Dietary bioaccumulation; PCDD/Fs; AhR gene
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2007.12.032

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 (∼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 ∼300 days of exposure. However, no effect on the antioxidant enzymes CAT and t-GPX was found.