芘暴露对马氏珠母贝鳃和肝胰腺抗氧化酶活性的影响

在实验生态条件下，采用生态毒理学方法，选用海洋环境中常见的有机污染物多环芳烃芘（Pyrene），以马氏珠母贝（Pinctada martensi）为实验材料进行毒理实验。研究了芘不同质量浓度（8、16、32和64μg·L^-1、不同时间（7，10 d）的胁迫对马氏珠母贝鳃和肝胰腺组织中超氧化物歧化酶（SOD）、过氧化物酶（POD）和谷胱甘肽过氧化物酶（GPx）3种抗氧化酶活性的影响。结果表明：3种酶在不同组织和不同胁迫时间的敏感性有所差异，在芘胁迫马氏珠母贝第7天，鳃组织中 SOD、POD、GPx 3种酶活性主要表现为诱导现象，高质量浓度组对3种酶活性均具有极显著诱导作用（p〈0.01），而芘胁迫对肝胰腺3种酶活性的影响主要表现为抑制作用，且POD酶活性表现最敏感，在较低浓度组就被显著抑制（p〈0.01）；到染毒第10天，鳃组织中SOD、GPx两种酶诱导作用明显，POD诱导现象不显著（p〉0.05），肝胰腺中3种酶活性与对照组相比诱导明显，并表现出一定的剂效关系。两种组织中SOD和GPx活性的变化具有一定的同步性。通过比较最低可观察效应质量浓度（LOEC），发现在第7天，鳃组织中敏感性强弱表现为SOD=POD〉GPx，肝胰腺中表现为POD〉GPx〉SOD，而到第10d，两组织中敏感性又分别表现为GPx〉SOD〉POD，GPx=SOD〉POD。因此，在较短的暴露时间，POD酶活性可作为芘胁迫对马氏珠母贝的生物标志物，而对于较长时间的染毒实验，可选用 GPx 酶作为芘胁迫对马氏珠母贝的生物标志物以监测海洋环境芘污染。

The effects of pyrene exposure on antioxidant enzymes activity in the gill and hepatopancreas of pearl oyster Pinctada martensi

The toxicological experiment of pearl oyster Pinctada martensi in the experimental conditions exposed by the marine pollutant Polycyclic aromatic hydrocarbon-Pyrene was examed using the method of ecotoxicology. After exposure to four different Pyr concentrations （8, 16, 32 and 64 μg·L^-1nd two different times（7, 10 d）, the activities of antioxidant enzymes superoxide dismutase （SOD）, peroxidase（POD） and glutathione peroxidase （GPx） in gill and hepatopancreas of Pinctada martensi were evaluated. The results showed that：the sensitivity of enzyme activitis varies during time-depentent changes and different tissues. In 7d, The activities of superoxide dismutase （SOD）、peroxidase（POD）and glutathione peroxidase （GPx） in gill were induced and there was a significant effect at higher concentration（p〈0.01）, while the activities were inhibited in hepatopancrea, the POD activity was the most sensitive and significantly inhibited at lower concentration（p〈0.01）;In 10d,both SOD and GPx activities were induced in gill, yet there was no significant effect in POD（p〉 0.05）, compared to the control group, three enzymes activities were induced remarkably, there existed a significant concentration-effect relationship between enzymes activities and the concentration of Pyrene. These changes in SOD and GPx activities in gill and hepatopancreas tissues occurred synchronously. Finally, comparison of the lowest-observed-effect concentration （LOEC） indicated that the sensitivity of three enzymes to was SOD=POD〉GPx, which was POD〉GPx〉SOD in hepatopancrea, at 10d, the sensitivity in two tissues was GPx〉SOD〉POD, GPx=SOD〉POD, respectively. Thus, in a relatively short exposure time, POD activity as a biomarker could better indicate the ecotoxicological effect of Pyrene in pearl oyster, while for a longer time exposure experiments, the GPx enzyme can be used as one of the biomarkers for monitoring marine Pyrene contamination .