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The organophosphate insecticide of chlorpyrifos (Chlorpyrifos) is a broad spectrum, and its chemical name is O, O-diethyl-O-(3,5,6 - trichloro-2 - pyridinyl) phosphorothioate, mainly applied to agricultural pests and urban family health pests. Chlorpyrifos is one of the world's most widely used pesticides, residual toxicity problem has drawn wide attention. TCP (3,5,6 - trichloro - 2 - pyridinol) is the major metabolite of chlorpyrifos, due to the widespread use of chlorpyrifos, resulting in the environment there is a certain amount of TCP. TCP than chlorpyrifos has a more powerful water-soluble and liquidity, making it easier to penetrate the water, pollution of underground and surface water bodies, environmental biological harm. Although TCP has the potential harmful effects of environmental biotechnology, but only a few studies have been reported. Chlorpyrifos and TCP selected zebrafish indicator organism, the zebrafish females and males were exposed to the blank control and 0.01,0.1,1 mg / L chlorpyrifos, 0.01,0.1,0.5 mg / L TCP different concentrations The 5,10,15,20,25 d after exposure of the sample to measure the solution. Chlorpyrifos and TCP zebrafish DNA damage, liver microsomal cytochrome P450 content, NADPH-cytochrome P450 reductase (NCR) activity, catalase (CAT) activity, superoxide dismutase (SOD) activity, reactive oxygen species (ROS). Evaluation of chlorpyrifos and its degradation the product TCP ecological toxicity and genotoxicity, and provide the basis for a comprehensive knowledge and understanding of chlorpyrifos and TCP aquatic ecosystems. The main findings are as follows: 1. Single cell gel electrophoresis (SCGE): can be caused by the different concentrations of chlorpyrifos and TCP processing zebrafish cell DNA damage, and along with the increase of the concentration and time to extend the length of the comet tail, Olive the upward trend of the value of the tail moment, indicating the degree of DNA damage and chlorpyrifos and TCP concentration and processing time in a dose - effect and time - effect relationship. Meanwhile, the impact of TCP zebrafish liver microsomes cell DNA seen by comparing same conditions chlorpyrifos, chlorpyrifos degradation product TCP genotoxic greater than chlorpyrifos. 2.P450 enzymes: select the content of cytochrome P450 P450 enzymes, NCR as an indicator. Chlorpyrifos and TCP processing group the indicators activity are always above the level of the control group during the whole experiment. P450 content via TCP exposure of each treatment group, NCR, respectively, higher than the same concentration of chlorpyrifos treatment group, indicating that TCP zebrafish and more intense, more toxic than chlorpyrifos. In addition, the study also showed that chlorpyrifos and TCP in zebrafish P450 enzymes gender differences, females P450 content and NCR activity was significantly higher than the male, female than male more sensitive and vulnerable. 3 the antioxidant enzymes Department: antioxidant enzyme system in SOD and CAT activities as an indicator. Course of the experiment, with the exposure time, the antioxidant enzyme activity at low concentrations (0.01,0.1 mg / L) treatment groups increased at high concentrations (0.5,1 mg / L) treated lower, but significant higher than those in the control group indicator active. This indicates that the activation of chlorpyrifos on antioxidant enzyme system of zebrafish. Zebrafish chlorpyrifos and TCP under the body by toxicity against its antioxidant enzyme system play a role, in order to resist the toxic effects of external contamination. Under the same conditions, the activity of antioxidant enzymes indicators affected by the TCP higher than chlorpyrifos, TCP zebrafish and more intense, more toxic than chlorpyrifos. Reactive oxygen (ROS): During the experiment, compared with the control group, the treatment group ROS activity was significantly increased with the increase in the exposure time and exposure doses. TCP under the influence of the zebrafish hepatic microsomal ROS activity was significantly higher than that of the chlorpyrifos treatment group activity under the same conditions, showed that more strongly TCP zebrafish, compared with chlorpyrifos further evidence is concerned, TCP has greater toxicity.
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