潮间带原油污染对泥蚶(Tegillarca granosa)抗氧化酶活性影响与综合生物标志物响应研究

随着海洋石油开发及运输的不断发展，溢油事故时有发生，给潮间带生物带来不同程度的影响. 以泥蚶(Tegillarca granosa)为研究对象，采用潮间带原油污染生物暴露室内模拟试验及数据统计检验，结合综合生物标志物响应(IBR)星状图，探讨潮间带沉积物原油污染对泥蚶鳃和消化腺中不同抗氧化酶活性的影响，筛选最优生物标志物. 结果表明:①受低浓度原油污染时超氧化物歧化酶(SOD)活性总体表现为被诱导，受高浓度原油污染时总体表现为被抑制，且其在消化腺中的平均活性(132.29 U/mg)约为鳃中(69.34 U/mg)的2倍. ②过氧化氢酶(CAT)活性在时间-效应上与SOD活性变化规律相似，但其响应时间具有滞后性. ③鳃中谷胱甘肽转硫酶(GST)活性在受污染第1天总体表现为被抑制，而消化腺中GST活性在第3、12天时被抑制的效果更明显. ④鳃中谷胱甘肽过氧化物酶(GPx)活性在污染第3天较早被激发，且消化腺中GPx活性最大诱导率和抑制率都出现在低浓度(500 mg/kg)原油污染时. ⑤泥蚶鳃和消化腺的IBR值均随暴露时间的增加呈先降低后升高的趋势，且与4种酶活性变化趋势基本相同. 研究显示，4种主要抗氧化酶在消除活性氧自由基(ROS)上具有协同作用，GST可作为原油污染短期监测的生物标志物，而IBR可作为综合生物毒性评价的指标. 

Effects of Intertidal Crude Oil Pollutionon on Antioxidant Enzyme Activity of Tegillarca granosa and Integrated Biomarker Response

With the development of offshore oil exploitation and transportation, oil spill accidents happen frequently, which affect intertidal organisms at different degree. Taking Tegillarca granosa as the research object, the effects of crude oil pollution in intertidal sediments on the activities of different antioxidant enzymes in the gills and digestive gland of Tegillarca granosa were investigated through indoor simulation of intertidal oil pollution biological exposure and statistical test of data combined with integrated biomarker response (IBR) star plots, and at last the optimal biomarker was screened. The results showed that: (1) The activities of superoxide dismutase ( SOD ) was induced by low concentration of crude oil pollution, and inhibited by high concentration of crude oil pollution. The average enzyme activity of digestive gland (132.29 U/mg) was about twice that of gills (69.34 U/mg). (2) Except that catalase(CAT) response was later, its time-effect was similar to that of SOD. (3) The activities of glutathione S-transferase (GST) in gills were generally inhibited on the first day of contamination, while the inhibitory effect was more obvious on the third and twelfth days in digestive gland. (4) The glutathione peroxidase (GPx) activities in gills were stimulated earlier on the third day of contamination, while the maximum induction rate and inhibition rate of digestive gland in GPx activities appeared at low crude oil concentration (500 mg/kg). (5) The IBR values about gills and digestive gland of Tegillarca granosa decreased first and then increased with the exposure time increase, and the trends were basically the same as those of the four enzymes activities. The studies showed that the four major antioxidant enzymes had a synergistic effect on eliminating reactive oxygen species (ROS), GST could be used as a biomarker for short-term monitoring of crude oil pollution, and IBR could be used as an index for comprehensive biotoxicity evaluation.