The Study On Sub-lethal Toxic Effects And Biomarkers Of Anthracene To Mytilus Galloprpvincialis

Due to the development of economy and population growth in coastal areas, themarine pollution caused by a variety of organic pollutants, especially the pollution ofcoastal waters is increasingly serious. Polycyclic aromatic hydrocarbons (PAHs) is akind of persistent organic pollutants, exist widely in the environment, and has strongcarcinogenicity, mutagenicity, toxicity. PAHs has a great threat to the environment andhuman health, considered as one of the priority control pollutants in the list ofinternational environmental protection agency.Detoxification usually occurs in two major steps: mixed function oxygenases(MFO) such as7-ethoxyresorufin-o-deethylase (EROD) make modification of themolecule to render it more polar, followed by conjugation so that the foreign materialcan be excrected. In this process, often accompanied by the generation of reactiveoxygen species (ROS), reactive oxygen species (ROS) can be eliminated by antioxidantdefense system including superoxide dismutase (SOD), glutathione peroxidase(GSH-Px) and catalase (CAT) within a certain range. But when the antioxidant defensesystem can not eliminate these reactive oxygen species (ROS), it can cause lipidoxidation, DNA and protein damage and other toxic effects.Study the subacute toxic effects of Mytilus galloprovincialis in the frequentenvironment polluted by PAHs-anthracene. This paper has studied the effects of ANTon the activity of a kind of detoxicant enzymes-7-ethoxyresorufin-o-deethylase(EROD) in the digestive gland of the mussels under long-term sublethal stress. Theeffects on three kinds of antioxidant enzymes involving in metabolism of organicpollutants-superoxide dismutase (SOD)、glutathione peroxidase (GSH-Px)andcatalase (CAT) of two different tissues-digestive gland and gill have also been studied, after different concentrations and long-term sublethal stress of ANT of themussels. Analysis the possible pathways and mechanisms of the ANT stress on themussels. In order to screen out the representative and high-sensitive molecularbiomarkers for ANT stress. Results show that:1.The effects of sublethal stress of ANT on one kind of detoxicant enzymes-ERODof M. galloprpvincialisIn the21-day ANT exposure period, there is no significant change in the ERODactivity of5.29ng/L concentration group (P>0.05). The EROD activities of64.26ng/Lconcentration group and332.04ng/L concentration group are significantly induced(P<0.05) after7days ANT exposured. With time, The EROD activities of64.26ng/Lconcentration group are back to the normal levels. The EROD activities of332.04ng/Lconcentration group are significantly induced (P<0.01) after21days ANT exposured.There is a high correlation between EROD activities and ANT concentrations, showeda good dose-effect relationship. EROD activities in digestive glands of M.galloprpvincialis were very sensitive to the responses of long-time, high-concentrationANT stress, and can be used as the high-sensitive biomarkers for ANT stress.2. The effects of sublethal stress of ANT on three kinds of antioxidant enzymes indigestive glands and gills of M. galloprpvincialisThe changes of SOD, CAT, GPx activities in digestive glands of M.galloprpvincialis show a good dose-effect and a good time-effect relationship withANT concentrations. SOD, CAT, GPx activities in digestive glands compared with thecontrol groups in general have a trend of induction at first, then the trend changes toinhibition with time, and the inhibited time of64.26ng/L,332.04ng/L concentrationgroups are ahead the inhibited time of5.29ng/L concentration group. In gills, SOD,CAT, GPx activities have response to ANT stress within3days. The changes of SOD,CAT, GPx activities in gills of64.26ng/L,332.04ng/L concentration groups have thesimilar model with the changes in digestive glands, that is,“induced-inhibited” model.The mussels’ digestive gland is more sensitive under long-time sublethal stress of ANT,and it is the primary target organ. SOD activities, CAT activities are very sensitive tothe responses of ANT stress and can be used as the high-sensitive biomarkers for ANTstress. 3. Preliminary analysis of the integrated biomarker response index (IBR) underANT stressTake SOD, CAT, GPx activities in digestive glands and gills as biomarkers,establish the comprehensive evaluation index of multiple biomarkers based on theintegrated biomarker responses index (IBR). The change of IBR value of M.galloprpvincialis showed a good time-effect relationship under different concentrationsANT stress, that is, the longer time mussels affected by ANT stress, the lower the valueof IBR. Between IBR value of each experimental group and the exposureconcentrations, exposure time IBR values with increasing exposure concentrationsbasic showing first increased and then decreased.