【作者】 隗黎丽；

【导师】 张世萍；

【作者基本信息】 华中农业大学 ， 水产养殖， 2004， 硕士

【摘要】 本试验研究的目的是为了评价三唑磷对黄鳝的毒性效应，从而为生产实践提供理论指导。利用生理、生物化学和石蜡切片等方法进行了以下几个方面的研究：三唑磷对黄鳝胚胎孵化的影响；对黄鳝不同发育阶段的急性毒性效应；对黄鳝外周血红细胞的致突变效应和血液生理指标的影响；对黄鳝脑AChE酶活性的影响和三唑磷对黄鳝肝脏组织显微结构的影响。结果表明： 1．三唑磷严重影响了黄鳝胚胎的孵化，使孵化率降低，出膜时间推迟，黄鳝胚胎孵化率随三唑磷浓度的升高而下降，在115h时，浓度．反应回归方程为y=4.59-1.02x（x：浓度对数，y：孵化率概率单位：r=0.98）； 2．三唑磷对黄鳝的急性毒性随黄鳝的发育阶段表现出先增大后减小的特点，胚胎96h LC₅₀为1.08mg／L、平均全长1.80 cm规格黄鳝96h LC₅₀为0.25mg／L、平均全长28.00cm规格黄鳝96h LC₅₀为0.32mg／L，试验中以平均全长1.80cm规格的黄鳝对三唑磷最为敏感； 3．三唑磷对黄鳝有一定的致突变效应，黄鳝染毒后，黄鳝外周血红细胞微核率、核异常率和总核异常率随着浓度的增大，遗传毒性呈现上升的趋势。随着染毒时间的延长，各染毒浓度组均出现了一个时间高峰值，在高峰值之后，黄鳝的微核率、核异常率和总核异常率并不随之上升，反而下降，并不表现时间效应。黄鳝各个染毒浓度组红细胞微核率达到最大值的时间不一致，0.160mg／L浓度组最早达到最大值，差异显著（p＜0.05），另外，核异常率出现高峰的时间晚于微核率出现高峰的时间： 4．三唑磷对黄鳝有一定的生理毒性。黄鳝染毒后，红细胞数和血红蛋白有不同程度的下降，与对照组相比，各个浓度组，在处理24h后均无显著差异（p＞0.05），而在处理96h和168h后，则均有显著差异（p＜0.05）； 5．活体条件下三唑磷对黄鳝脑AChE活性有显著影响。随着黄鳝在三唑磷溶液中暴露浓度的增大或暴露时间的延长，脑AChE的活性逐渐降低，受到抑制的程度逐渐增大，与对照组相比差异显著（19＜0.05）： 6．三唑磷对黄鳝肝脏组织的显微结构有很明显的影响，随着暴露时间的延长或浓度的增大，肝脏组织的破坏程度越来越严重，主要症状有：淤血，肝细胞膨胀，核偏移，细胞膜界限模糊，细胞质水肿。更多还原

【Abstract】 The aims of the present study were to assess the toxic effects of triazophos on the Monopterus albus. The effects of triazophos on the hatchability of embryos and the acute toxicities of triazophos on the different developmental stages of Monopterus albus, the inducing effects on micronucleated erythrocytes and the effects on blood physiological indexs of Monopterus albus, the effects on the activities of brain AChE and the effects on the liver tissue’s microstructure of Monopterus albus were studied in this paper. The main results were summarized as follows:1. Resulting in the low hatchability and the later hatchability compared with control group, triazophos had great effects on the hatchability of embryos of Monopterus albus. The hatchability were reduced when triazophos concentration were increased, the regression equation of concentration-response relation in 115h was y=4.59-1.02x (x: concentration logarithm, y: probability unit of hatchability, r=0.98);2. The acute toxicities of triazophos on different development stages of Monopterus albus showed embryo was not most sensitive and the fry with average total length 1.80cm was most sensitive, the 96h LCso of embryo, fry with average total length 1.80cm and Monopterus albus with average total length 28.00cm respectively was: 1.08mg/L 0.25mg/L 0.32mg/L;3. Micronuclei test of Monopterus albus was applied to study possible mutagenic activities of triazophos. Monopterus albus were exposed to triazophos with five concentrations of 0.160 mg/L 0.107 mg/L 0.080mg/L 0.053 mg/L and 0.032mg/L for seven days. The test results indicated that triazophos could increase the frequency of micronuclei, nuclear anomalies and total nuclear anomalies erythrocytes. At certain range of triazophos concentration, the frequency of micronucleated erythrocytes showed a dosage-dependent elevation. In addition, with the increasing of the dosages, the high frequency of micronucleated erythrocytes appeared also earlier, and the high frequency of nuclear anomalies erythrocytes appeared later than the high frequency of micronucleated erythrocytes. In a word, triazophos had mutagenic actions to the erythrocytes of Monopterus albus;4. Hemoglobin and erythrocyte in the test groups were dropped, all test groups exposed for 96h and 168h compared with control group, the differences were significant at the 0.05 level (p<0.05), but there were not significant differences at the 0.05 level(p>0.05) when all test groups exposed for 24h;5. Triazophos had significant effects on the activities of brain AChE of Monopterus albus in vivo. With the concentration augmented or the time prolonged, the activities of brain AChE of Monopterus albus were dropped gradually, and the restraining degree gradually increased, the difference were significant at the 0.05 level (p<0.05) when all test groups compared with control group;6. Significant differences in the liver tissue of microstructure were found, with the concentration augmented or the time prolonged, the destroying degree of liver tissue was more significant: the boundary of cell membrane became indistinct, hepatocytes were obviously swollen, karyon were mostly pushed to one side of the cytoplasm and congestion was in the liver.更多还原