Precision-Cut Liver Slices of Salmo salar as a tool to investigate the oxidative impact of CYP1A-mediated PCB 126 and 3-methylcholanthrene metabolism.
Fish isolated cell systems have long been used to predict in vivo toxicity of man-made chemicals. In present study, we tested the suitability of Precision-Cut Liver Slices (PCLS) as an alternative to these models that allows the evaluation of a global tissue response to toxicants, to investigate oxidative stress response to cytochrome P450 1A (CYP1A) induction in fish liver. PCLS of Salmo salar were exposed for 21 h to increasing doses of 3-methylcholanthrene (3-MC) and Polychlorobiphenyl 126 (PCB 126). 3-MC (25 μM) strongly induced CYP1A transcription. In dose-response analysis (25-100 μM), EROD activity was strongly increased at intermediate 3-MC concentrations. We found the counter-intuitive decline of EROD at the highest 3-MC doses to result from reversible competition with ethoxyresorufin. No increases of H(2)O(2) production, antioxidant enzymes activities or oxidative damage to lipids were found with 3-MC treatments. PCLS subjected to PCB 126 (2-200 nM) showed increased contamination levels and a parallel increased CYP1A mRNA synthesis and EROD activity. H(2)O(2) production tended to increase but no oxidative damage to lipids was found. As antioxidant enzymes activities declined at the highest PCB 126 dose, it is suggested that longer incubation periods could be required to generate oxidative stress in PCLS.
Institut des Sciences de la Vie, Université catholique de Louvain, Louvain-la-Neuve, Belgium.
Benjamin
B
Lemaire
Michaël
M
Beck
Mélanie
M
Jaspart
Cathy
C
Debier
Pedro Buc
PB
Calderon
Jean-Pierre
JP
Thomé
Jean-François
JF
Rees
D000818:Animals; D002950:Citrate (si)-Synthase / Q000378:metabolism; D019363:Cytochrome P-450 CYP1A1 / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D004790:Enzyme Induction / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D008748:Methylcholanthrene / Q000633:toxicity*; D009924:Organ Culture Techniques; D009994:Osmolar Concentration; D018384:Oxidative Stress / Q000187:drug effects*; D010088:Oxidoreductases / Q000378:metabolism; D011078:Polychlorinated Biphenyls / Q000032:analysis / Q000633:toxicity*; D012333:RNA, Messenger / Q000378:metabolism; D020317:Salmo salar; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D013997:Time Factors; D018675:Toxicity Tests; D014874:Water Pollutants, Chemical / Q000633:toxicity*
D012333:RNA, Messenger; D017392:Thiobarbituric Acid Reactive Substances; D014874:Water Pollutants, Chemical; D008748:Methylcholanthrene; D006861:Hydrogen Peroxide; D011078:Polychlorinated Biphenyls; D010088:Oxidoreductases; D019363:Cytochrome P-450 CYP1A1; D002950:Citrate (si)-Synthase; C023035:3,4,5,3',4'-pentachlorobiphenyl