苯并(a)芘和苯并(k)荧蒽混合物对栉孔扇贝毒理学指标的影响

Effects of benzo(a)pyrene and benzo(k)fluoranthene mixture on the toxicology parameter of scallop Chlamys farreri

检测了暴露于不同浓度多环芳烃中栉孔扇贝(Chlamysfarreri)消化盲囊和鳃丝的几项毒理学指标变化.苯并(a)芘和苯并(k)荧蒽混合物的浓度梯度设置为0.5、1.0、10.0、50.0μg·L-1.结果表明,低浓度PAHs对消化盲囊EROD活力无显著影响,对GST有一定的诱导作用,而高浓度PAHs对消化盲囊EROD有明显的诱导作用,对GST先诱导后抑制;在PAHs作用下消化盲囊和鳃丝的3种抗氧化酶(SOD、CAT和GPx)活力呈现一定的峰值变化,且在高浓度PAHs下均被显著抑制,同时鳃丝的酶活力较消化盲囊抑制显著;消化盲囊和鳃丝的LPO水平在PAHs处理下随时间不断上升,并表现出明显的剂量和时间效应.暴露于PAHs中栉孔扇贝的EROD、GST和抗氧化酶活力的变化反映了机体的解毒代谢过程和能力,而LPO水平则直接反映了机体的氧化损伤程度,而且各毒理学指标在解毒过程中相互关联,具有很强的规律性.

The effects of Benzo （a） pyrene and benzo （k） flouranthene mixture on EROD, GST, antioxidant enzymes activities and LPO levels of digestive gland and gills of scallop Chlamys Ferrari were studied. The results indicated that there is no significant effect on EROD activity in digestive gland at low concentrations （0.5 μg· L^-1 and 1.0 μg· L^- 1 ） of PAHs, whereas it has induced the GST activity, that while in high concentration （ 10.0 μg· L^-1 and 50.0 μg· L^-1 ） of PAHs, EROD activity increased significantly, and the GST activity showed peak changes. Three antioxidant enzymes （SOD,CAT and GPx） all showed great changes and were restrained in high PAHs concentrations. Furthermore the gill was more sensitive to BaP than digestive gland, and its detoxification function was less strong than digestive gland, which indicated that digestive gland was the main tissue to metabolize oxyradicals. The contents of MDA increased with the treating time, and a positive correlation （concentration-effect） was shown between the MDA contents and the concentrations of the PAHs exposure. According to the studies, the increase of EROD, the decrease of GST and the changes of antioxidant enzymes can reflect the toxicity of PAHs. Therefore the LPO levels showed as a direct biomarker reflecting the oxidant stress. Furthermore, an important relationship in detoxification of these biomarkers can be seen in the results.