石油烃暴露对栉孔扇贝(Chlamys farreri)组织生物转化酶及DNA损伤的影响

Effects of Petroleum Hydrocarbon Exposure on Biotransformation Enzymes Activities and DNA Damage of Scallop Chlamys farreri

为探讨海水中石油烃对栉孔扇贝生物转化酶和DNA损伤的影响,将栉孔扇贝分别置于含4个浓度梯度(0.1mg·L-1,0.3mg·L-1,1.0mg·L-1和3.0mg·L-1)石油烃的海水中进行为期30d的暴露实验,取消化盲囊和鳃丝分别测定其7-乙氧基异吩恶唑脱乙基酶(7-Ethoxy-Resorufin-O-Deethylase,EROD)、谷胱甘肽S转移酶(Glutathione S-Transferase,GST)活性和DNA损伤F值。结果显示,除0.1mg·L-1浓度组各指标变化不明显外,其余各处理组各指标随时间都出现不同程度的变化。消化盲囊和鳃丝EROD活力相对于对照组都明显被激活,消化盲囊EROD活力随时间内一直呈现上升趋势,在第30d达到最大值,而鳃丝EROD活力从3d后趋于稳定;消化盲囊和鳃丝GST酶活性在0.3mg·L-1处理组明显被激活,在其余两个高浓度组呈现先激活,最后显著被抑制的趋势,鳃丝GST酶活性被较早的抑制;消化盲囊和鳃丝DNA损伤F值在各浓度组随时间明显下降,呈现剂量-效应和时间-效应关系,鳃丝下降幅度较为明显。结果表明,扇贝对0.3mg·L-1以下浓度石油烃暴露具有一定的耐受性,可以通过提升自身生物转化酶活性等功能进行解毒,而对于1.0mg·L-1以上浓度的石油烃暴露,机体显示出明显的致毒效应,鳃丝受到损伤程度较消化盲囊明显,三种指标结合在一起研究能够反映机体受石油烃影响解毒和受损伤的过程,是较好的反映海水石油烃污染程度的生物学指标。

In order to study the effects of petroleum hydrocarbon in seawater on biotransformation enzymes and DNA damage of scallop Chlamys farreri, The scallops were cultured in seawater contained four concentration gradient petroleum hydrocarbon for 30 days, the concentration of petroleum hydro- carbon was 0. lmg · L^-1, 0. 3mg · L^-1, 1. 0mg · L^-1 and 3. 0mg · L^-1 separately, the 7-Ethoxy- Resorufin-O-Deethylase （EROD）, Glutathione S-Transferase （GST） activities and DNA F value were determined. The results showed that all biomarkers changed significantly in all experimental groups ex- cept 0. lmg · L^-1 group. The EROD activities of digestive gland and gills of Chlamys farreri were in- duced significantly, but EROD activities of digestive gland kept rising during all times and reached max- imum value at 30 d, EROD activities of gills showed stable trend from 3 d; GST activities of digestive gland and gills were induced significantly in 0.3mg · L^-1 group but it increased first and then restrained at last time in other two treatment groups of higher concentrations, the GST activities of gills were re- strained earlier than digestive gland; The DNA F values of two tissues decreased significantly and showed the time-effect and dose-effect characteristics, the DNA F value of gills decreased more signifi- cantly than digestive gland. The results indicated that Chlamys farreri can bear the petroleum hydro- carbon less than 0.3mg · L^-1 concentration in seawater, but it showed significant toxic effect if the con- centrations of petroleum hydrocarbon in seawater were higher than 1.0mg·L^-1 , the damage of gills was more significantly than digestive gland. The three biomarkers in this experiment had the relations of initiative detoxification and passive damage, it can reflect the detoxification function and damage process of scallop Chlamys farreri for petroleum hydrocarbon, and they can be used as the biomarkers to evaluate the pollution degree of marine petroleum hydrocarbon.