苯并[a]芘对马氏珠母贝鳃组织抗氧化酶活性的影响

将马氏珠母贝（Pinctada martensi）暴露于不同质量浓度（1、4和8μg.L-1）苯并[a]芘B[a]P中,检测暴露后第3、7和10天后,马氏珠母贝鳃组织抗氧化酶（超氧化物歧化酶SOD、谷胱甘肽硫转移酶GST和过氧化氢酶CAT）对苯并[a]芘胁迫的生态毒理效应。结果表明：暴露时间为3、7 d时,SOD活性无明显变化,随着暴露时间的延长,SOD活性在第10天时被激活;在胁迫初期,GST活性被激活,随后表现出逐渐降低的趋势,在暴露后10 d,不同质量浓度组GST活性变化趋于稳定。当暴露质量浓度相同时,表现出明显的时—效关系;而CAT活性在第7天被激活,随着时间的延长,高质量浓度（4和8μg.L-1）组表现出先升高后下降的趋势,并表现出一定的时-效关系。SOD、GST和CAT均可作为B[a]P污染的生物标志物,活性变化相对于SOD,GST和CAT对B[a]P的胁迫更加敏感。

Effects of B [a] P on activity of antioxidant enzyme in gill of Pinctada martensi

Ecotoxicological effects of B[a]P on activity of superoxide dismutase（SOD）,glutathione S／｜transferase（GST） and catalase（CAT） in gill of Japanese pearl oyster（Pinctada martensi） as a model animal have been studied after exposure to B[a]P for 3,7 and 10 days respectively at three different B[a]P concentrations（1,4 and 8 μg.L-1）.The results showed that no significant influence of concentration of B[a]P on the activity of SOD was observed at 3rd and 7rd day.SOD activity was actived after exposure of 10th day in B[a]P.GST activity was increased at the beginning of exposure and depressed with increasing of exposure time.There exists a significant time-effect relationship between GST activity and exposure time of B[a]P.CAT activity was induced at the exposure of 7rd day of B[a]P and then depressed with increasing of exposure time.Similar trends between CAT activity and exposure time of B[a]P.has been observed.Compared with the activity of SOD,the variations of activity of GST and CAT enzyme as a biomarker could better indicate the ecotoxicological effects of B[a]P in gill of Pinctada martensi