Antioxidant response was used to assess the effects of the main pollutants in wild mussels (Mytilus galloprovincialis) along the Mediterranean coast of Spain. Antioxidant enzyme activities - those of catalase, superoxide dismutase, glutathione peroxidases, glutathione reductase, glutathione S-transferase and DT-diaphorase - as well as lipid peroxidation and metallothionein concentrations were measured in gills of mussels from 16 selected sites. Furthermore, concentrations of the main contaminants (Hg, Pb, Cd, Cu, Zn, As, PAH, PCB, and DDT) were quantified in mussel tissue, and environmental parameters were measured in water samples collected at each site. Results showed that the glutathione-dependent antioxidant enzymes offered an increased and coordinated response against metal (Hg, Pb and Cd) contamination. These enzymatic activities correlated positively to temperature, suggesting the influence of this environmental parameter on antioxidant responses in gill tissues. Furthermore, although temperature did not reach stressful levels in the study area, it seemed to add a synergistic effect to that produced by metals to induce antioxidant enzymes in the most metal-polluted sites. Catalase activity appeared to be involved in a different antioxidant pathway, more related to organic pollutant bioaccumulation, offering an efficient protection mechanism against reactive oxygen species generation due both to organic exposure and high physiological activity, reflected by high condition indices. In general terms, increased levels of antioxidant enzymes at some sites suffering from metal and organic pollution indicated a situation of oxidative stress that nevertheless did not appear to be harmful, since lipid peroxidation levels showed no peroxidative damage in gill tissues of mussels collected from even the most heavily polluted sites. On the other hand, metallothionein and DT-diaphorase did not reflect pollutant exposure and seemed to be more influenced by environmental variables than by the pollutants.
"lls . Similar findings were reported in C . edule from Ria de Aveiro by Freitas et al . ( 2012a ) . Also Torres et al . ( 2002 ) showed that the activity of SOD was not induced in the mussel Mytella guya - nensis from polluted areas , despite induction of CAT activity . However , the induction of GSTs , SOD activity and GSH was clearly reported by Fern andez et al . ( 2010 ) , in M . galloprovincialis from metal polluted sites , suggesting that higher pollutant stress may have induce GSTs , GSH and SOD expression in xenobiotic damage . Also Wang et al . ( 2012 ) reported that R . philippinarum transplanted to polluted areas in Maluan Bay ( China ) presented an increase of SOD , CAT and GSTs activity , sug"
"Krishnakumar et al. (1995) reported higher CAT activity in the digestive gland of mussels from contaminated sites when compared to those sampled at a reference site in the North American Pacific coast. Consistently, increased antioxidant activities were found in bivalves from contaminated sites in terms of PCBs, PAHs and pesticides (De Luca-Abbott et al., 2005; Fernandez et al., 2010). In the present study, the results also suggest that HPAH and/or DDT contamination increase the MDA levels in the gills and digestive gland. "
[Show abstract][Hide abstract] ABSTRACT: Contaminant effects on defence responses of ecologically and economically important organisms, such as the Pacific oyster Crassostrea gigas, are likely to influence their ability to resist infectious diseases, particularly at the young stages. The aim of this study was to explore the potential relationships between organic contaminants accumulated in the soft tissues of juvenile oysters, defence responses and physiological condition. Oysters were transplanted during summer and winter periods in different sites in the Marennes-Oléron Bay, the first area of oyster production in France, and in the Gironde Estuary, the biggest estuary in Occidental Europe. Amongst the battery of biochemical and physiological biomarkers applied in the present work [superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), malondyaldehyde (MDA), catecholase, laccase and lysozyme in gills, digestive glands, mantle and haemolymph, glycogen, proteins and lipids in the digestive gland and the condition index at the whole-organism level], MDA and lysozyme in the digestive gland and SOD, GPx and laccase in plasma contributed in order to significantly discriminate the sites in which oysters bioaccumulated different levels of heavy polycyclic aromatic hydrocarbons (HPAHs), polychlorobiphenyls (PCBs), polybromodiphenylethers (PBDEs), dichlorodiphenyltrichloroethanes (DDTs) and lindane. These results strengthen the hypothesis that it is possible to differentiate sites depending on their contamination levels and biological effects by carrying out studies with transplanted juvenile oysters. In addition, correlations were found between antioxidant and immune-defence responses, and PAH and DDT body burdens in the first area of oyster production in France (the Marennes-Oléron Bay) and where considerable oyster mortalities have been reported. This result suggests that the presence of organic chemical contaminants in the Marennes-Oléron Bay may influence defence responses in juveniles of C. gigas, and, therefore, could influence their ability to resist infectious diseases.
Science of The Total Environment 02/2015; 514. DOI:10.1016/j.scitotenv.2014.10.050 · 4.10 Impact Factor
"SODs (CuZnSOD and MnSOD being respectively the cytosolic and the mitochondrial form) are known to catalyze the dismutation of superoxide anions into hydrogen peroxides, which are in turn reduced by CAT into water and molecular oxygen. The increase of these antioxidant enzymes in response to effluent exposure seems to constitute an adaptation in gills to prevent and/or repair metal-induced damage in cellular component (Fernandez et al. 2010). Several studies have shown that metals can promote oxidative stress in cells (Sabatini et al. 2011; Trevisan et al. 2014; Wang et al. 2010), and in particular, Kamel et al. (2012) found a correlation between CAT, MnSOD, and metal accumulations in clams treated with municipal effluents. "
[Show abstract][Hide abstract] ABSTRACT: This study assessed the responses of molecular biomarkers and heavy metal levels in Cerastoderma glaucum exposed for 1 week to two industrial effluents (1 %) discharged into the Tunisian coastal area, F1 and F2, produced by different units of production of a phosphate treatment plant. A significant uptake of metals (Cd, Cu, Zn, and Ni) was observed in exposed cockles compared to controls, with an uptake higher for F1 than for F2. A decrease in LT50 (stress on stress test) was also observed after an exposure to the effluent F1. Treatments resulted in different patterns of messenger RNA (mRNA) expression of the different genes tested in this report. Gene transcription monitoring performed on seven genes potentially involved in the tolerance to metal exposure showed that for both exposures, mechanisms are rapidly and synchronically settled down to prevent damage to cellular components, by (1) handling and exporting out metal ions through the up-regulation of ATP-binding cassette xenobiotic transporter (ABCB1) and metallothionein (MT), (2) increasing the mRNA expression of antioxidant enzymes (catalase (CAT), superoxide dismutases, CuZnSOD and MnSOD), (3) protecting and/or repairing proteins through the expression of heat shock protein 70 (HSP70) mRNAs, and (4) increasing ATP production (through the up-regulation of cytochrome c oxidase 1 (CO1)) to provide energy for cells to tolerate stress exposure. The tools developed may be useful both for future control strategies and for the use of the cockle C. glaucum as a sentinel species.
Environmental Science and Pollution Research 01/2015; DOI:10.1007/s11356-015-4108-4 · 2.83 Impact Factor
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