|Reference : Effects of Polychlorinated Biphenyls on Thyroid Hormone Physiology and Metabolism of Eur...|
|Scientific congresses and symposiums : Unpublished conference|
|Life sciences : Aquatic sciences & oceanology|
|Effects of Polychlorinated Biphenyls on Thyroid Hormone Physiology and Metabolism of European sea bass (Dicentrarchus labrax)|
|Schnitzler, Joseph [Université de Liège - ULg > Département des sciences et gestion de l'environnement > Océanologie >]|
|Klaren, Peter [ > > ]|
|Celis, Niko [ > > ]|
|Blust, Ronny [ > > ]|
|Covaci, Adrian [ > > ]|
|Thomé, Jean-Pierre [Université de Liège - ULg > Département des sciences et gestion de l'environnement > Ecologie animale et écotoxicologie >]|
|Das, Krishna [Université de Liège - ULg > Département des sciences et gestion de l'environnement > Océanologie >]|
|SETAC Europe: 20th Annual Meeting|
|[en] Thyroid ; endocrine disruption ; sea bass|
|[en] Studies in the laboratory have shown that a number of synthetic and natural chemicals can interfere with the endocrine system in fish. Among them, organic compounds such as pesticides and polychlorobiphenyls (PCBs) are well described endocrine disrupters. Of particular interest are effects on thyroid function, but data on effects of PCB exposure on these hormones and related metabolism has been lacking. We propose here a thorough approach to assess effects of these compounds on the thyroid function of European sea bass (Dicentrarchus labrax).
An experimental exposure of sea bass to commercial PCB mixtures has been designed to understand underlying toxicity mechanisms and effects on the thyroid system. After 120 days of exposure, muscular thyroid hormone concentrations and the main metabolic pathways for thyroid hormones (deiodination, glucuronidation and sulfatation) were assessed.
Exposure to environmental relevant doses of PCB (from 0.3 to 0.9 ppm [7 ICES PCB]). alters hepatic T4 outer ring deiodinase and T4 sulfatation whereas T4 glucuronidation was not affected. Owing to the extensive autoregulatory feedback at both central and peripheral levels, the thyroid hormone concentrations were preserved despite the PCB induced changes in thyroid hormone dynamics. At 10 times higher concentrations (10 ppm [7 ICES PCB]). an important depression of muscular T3 and T4 levels could be observed which are apparently caused by other mechanisms than metabolic pathways. Further analysis is required to evaluate thyroid gland function and secretion. These results support the observations made in our field study in wild sea bass (Dicentrarchus labrax) from coastal regions near several important European rivers mouths.
|Centre Interfacultaire de Recherches en Océanologie - MARE|
|Fonds pour la formation à la Recherche dans l'Industrie et dans l'Agriculture (Communauté française de Belgique) - FRIA|
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