石油烃暴露对文蛤和四角蛤蜊解毒指标影响的对比研究

以文蛤（Meretrix meretrix）和四角蛤蜊（Mactra veneriformis）为实验对象，将其暴露于石油烃浓度分别为0.1 mg/L，0.3 mg/L，1.0 mg/L和3.0 mg/L的海水中，并于实验开始后的0、0.5 d、1 d、3 d、6 d、10 d和15 d取样，并测定其消化盲囊和鳃丝谷胱甘肽硫转移酶（GST）和超氧化物歧化酶（SOD）活性。实验结果显示，两种蛤各组织GST和SOD酶活性在0.1 mg/L和0.3 mg/L处理组均明显高于对照组水平（P＜0.05）；除四角蛤蜊鳃丝GST酶活性一直被抑制外，其余两种蛤各组织酶活性在1.0 mg/L处理组都呈现先升高后被抑制的趋势；除文蛤消化盲囊SOD活性在暴露实验开始升高外，其余组织酶活性在3.0 mg/L处理组一直被抑制（P＜0.05）。通过比较发现四角蛤蜊GST和SOD酶活性升高率在0.1 mg/L和0.3 mg/L浓度组实验前期高于文蛤，但是在后期低于文蛤，在1.0 mg/L和3.0 mg/L浓度组四角蛤蜊酶活性抑制率明显高于文蛤（P＜0.05）。结果表明，石油烃暴露条件下四角蛤蜊较文蛤表现更敏感，可以优先作为石油烃污染指示生物，鳃丝各指标的变化较消化盲囊明显，可以优先作为指示组织；GST和SOD酶的变化趋势具有一定一致性，以后相关研究和实践中可以将这两种指标结合测定以评价石油烃及其它有机物污染带来的风险。

Comparative studies on detoxification biomarkers effects of clam Meretrix meretrix and Mactra veneriformis under petroleum hydrocarbons exposure

The clams Meretrix meretrix and Mactra veneriformis were used as experimental objects and cultured in seawater containing petroleum hydrocarbons.The petroleum hydrocarbon concentrations of seawater were 0.1 mg/L, 0.3 mg/L, 1.0 mg/L and 3.0 mg/L separately, with sampling occurring at day 0, 0.5 1, 3, 6, 10, 15.The glutathione s transferase GST and superoxide dismutase SOD activities were determined.The results showed that GST and SOD activities of two tissues were higher than controls in 0.1 and 0.3 mg/L exposure groups(P < 0.05).GST and SOD activities all increased first and then were restrained in later time except that the gills GST activities of clam Mactra veneriformis were restrained over whole time in 1.0 mg/L groups.The SOD and GST activities were all restrained over whole experimental time except that SOD activities of digestive gland of clam Meretrix meretrix increased in early time in 3.0 mg/L groups(P < 0.05).Through comparative studies, SOD and GST activities rise rats of clam Mactra veneriformis were higher than clam Meretrix meretrix in early time in 0.1 and 0.3 mg/L groups, and then were lower than Meretrix meretrix in last experimental time.The enzyme activities inhibition rates of clam Mactra veneriformis were higher than clam Meretrix meretrix in 1.0 and 3.0 mg/L groups(P < 0.05).The results indicated that clam Mactra veneriformis were more sensitive than clam Meretrix meretrix under petroleum hydrocarbons exposure, so the clam Mactra veneriformis can be used as the petroleum hydrocarbons pollution-indicating organism firstly.The tissue gills changed more significantly than digestive gland, so the gills can be used as the priority indicator tissue.The SOD and GST activities changes showed the same trend, therefore, the two biomarkers can be combined to evaluate the risk of petroleum hydrocarbons and other organic pollutants in the later researches and practice.