| Summary: | Deep-sea fish are highly contaminated with organochlorine compounds(OCs), which are persistent man-made chemicals. Because it is very difficult to maintain these fish alive for toxicological experiments, the real impact of such contamination remains unknown. By analysing liver samples of the deep-sea grenadier Coryphaenoides rupestris (200 - 2600 meter depth), we first observed signs of an oxidative impact linked to OCs' metabolism. The activity of the phase 1 detoxification cytochrome P4501A (CYP1A) enzyme was positively correlated to OCs loads and antioxidant enzymes activities (catalase, superoxide dismutase). Still, the magnitude of CYP1A induction was fairly low compared to the huge contamination. We then developed the precision-cut liver slices (PCLS) technology to study more in-depth the oxidative impact of OCs' metabolism on living liver cells of C. rupestris. Two shallow fish (Salmo salar, Dicentrarchus labrax) were also chosen as basis for comparison. Hyperbaric cylinders were used to investigate in this comparative study the effects of the high hydrostatic pressure (typical of the deep-sea) on the response of liver cells of these fish to contaminants, their pro- and anti-oxidant status and that of heat shock proteins (also known to participate in a general stress response to toxicants). Apart from the obtention of the first-ever data on living deep-sea fish liver cells, we found a striking pressure-dependent reduction of CYP1A induction in each species, suggesting that deep-sea fish might be less prone to the oxidative impact of OCs metabolism in their environment (a feature that might explain their high OCs loads). (BIOL 3) -- UCL, 2011
|
|---|