菲律宾蛤仔对镉、铜暴露的蓄积作用及其抗氧化酶系统的响应研究

Bioaccumulation and antioxidant responses in Manila clam( Ruditapes philippinarum) under cadmium and copper exposure

研究了镉(Cd)、铜(Cu)2种重金属单一暴露下菲律宾蛤仔(Ruditapes philippinarum)肝胰腺和鳃组织内的重金属富集特征和抗氧化酶活力变化特点。结果表明,蛤仔肝胰腺与鳃对Cd、Cu的富集量随重金属浓度与暴露时间的增加而增大,具有明显的浓度效应与时间效应;菲律宾蛤仔对Cd的富集能力高于Cu,且肝胰腺中重金属的蓄积量高于鳃;蛤仔肝胰腺和鳃组织中超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GPx)和谷胱甘肽硫转移酶(GST)活力在暴露的某些时段被显著诱导(P<0.05),但随暴露时间延长或重金属浓度增加,SOD和GST活力则被显著抑制(P<0.05),而GPx活力随暴露时间延长逐渐恢复至对照组水平。菲律宾蛤仔肝胰腺和鳃2种组织中SOD和GST的活性变化可作为海洋Cu2+、Cd2+污染的生物标志物。

We studied the bioaccumulation characteristics and antioxidant enzymes activity changes of Manila clam, Ruditapes philip- pinarum under the exposure to cadmium （Cd） and copper （Cu）. The bioconcentrations of Cd and Cu in gill and hepatopancreas of R. philippinarum showed obvious time and dose dependent responses. The clam showed higher bioaccumulation ability on Cd than that of Cu, and the heavy metal concentrations in hepatopancreas were greater than those in gill. Additionally, the acfivilies of superoxide dismutase （SOD）, glutathione peroxidases （GPx） and glutathione stransferases （GST） were significantly promoted in hepatopancreas and gill of R. philippinarum at difl＇erent concentrations and time intervals （ P 〈 0. 05 ） , while the activities of SOD and GST were sig- nificantly inhibited at high concentrations of Cd and Cu （P 〈 0. 05）. The activities of GPx recovered to the original level with the time progressed. Taken together, the changes of SOD and GST activities in hepatopancreas and gills of R. philippinarum could be consid- ered as potential biomarkers for copper and cadmium contamination in the marine environment.