Juvenile sea bass biotransformation, genotoxic and endocrine responses to β-naphthoflavone, 4-nonylphenol and 17β-estradiol individual and combined exposures
Teles, Mariana (University of Aveiro. Department of Biology)
Gravato, Carlos (University of Aveiro. Department of Biology)
Pacheco, M. Guilherme Garcês (University of Aveiro. Department of Biology)
Santos Maroño, Mauro (University of Aveiro. Department of Biology)

Data:	2004
Descripció:	12 pàg.
Resum:	Juvenile sea bass, Dicentrarchus labrax L. , were exposed during 2, 4, 8, and 24 h to 0. 9 μM β-naphthoflavone (BNF), 131 nM 17β-estradiol (E2), 4. 05 μM 4-nonylphenol (NP), as well as to BNF combined either to E2 or NP (maintaining the previous concentrations). Liver cytochrome P450 content (P450), ethoxyresorufin-O-deethylase (EROD), and glutathione S-transferase (GST) activities were measured in order to evaluate biotransformation responses. Genotoxicity was assessed as erythrocytic nuclear abnormalities (ENA) frequency. The effects on endocrine function were evaluated as plasma cortisol and glucose. Cortisol was not affected by xeno/estrogens tested, either in single exposure or mixed with BNF. Nevertheless, the intermediary metabolism was affected since glucose concentration increased after 4 h exposure to E2, and after all BNF+NP exposure lengths. Moreover, a synergism between BNF and NP was thoroughly demonstrated, whereas a sporadic antagonistic interaction was found at 4 h BNF+E2 exposure. Liver EROD and GST activities were not significantly altered by single E2 or NP exposure. However, both compounds were able to induce EROD activity in the presence of BNF. NP single exposure was able to significantly increase liver P450 content, while its mixture with BNF displayed an antagonistic interference. Considering the xeno/estrogens single exposures, only NP induced an ENA increase; however, both mixtures (BNF+E2 and BNF+NP) displayed genotoxic effects. Fish responses to mixtures of xenobiotics are complex and the type of interaction (synergism/potentiation or antagonism) in a particular mixture can vary with the evaluated biological response.
Drets:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, i la comunicació pública de l'obra, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original. No es permet la creació d'obres derivades.
Llengua:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Matèria:	Cortisol ; ENA ; Glucose ; GST ; P450 monooxygenases
Publicat a:	Chemosphere, Vol. 57, Num. 2 (October 2004) , p. 147-158, ISSN 1879-1298

DOI: 10.1016/j.chemosphere.2004.02.023
PMID: 15294438

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