重金属Cu^(2+),Pb^(2+)和Zn^(2+)胁迫对近江牡蛎(Crassostrea rivularis)SOD活性影响研究

Effects of heavy metals on superoxide dismutase (SOD) of Crassostrea rivularis

为探讨将近江牡蛎(Crassostrea rivularis)抗氧化酶防御体系参数作为海洋重金属污染生物监测指标可行性,文章在实验室条件下,研究这三种重金属暴露对近江牡蛎(C.rivularis)鳃和消化腺组织SOD活性的诱导作用;实验结果表明:Cu2+,Pb2+和Zn2+能诱导近江牡蛎(C.rivularis)腮和消化腺SOD的产生,但由于近江牡蛎(C.rivularis)腮和消化腺的结构和功能的不同,在重金属的诱导下,消化腺内的SOD活性要比腮的大;Pb2+和Zn2+诱导近江牡蛎(C.rivularis)鳃和消化腺组织SOD活性变化的剂量-效应均为抛物线型;Cu2+对近江牡蛎(C.rivularis)鳃组织SOD活性诱导曲线不呈抛物线型,而对消化腺组织SOD活性诱导的剂量-效应呈抛物线型;根据对SOD活性影响的强弱,三种重金属对近江牡蛎(C.rivularis)的毒性强弱顺序为Cu2+>Pb2+>Zn2+。在实验室条件下,近江牡蛎(C.rivularis)消化腺组织中的SOD活性可作为养殖水体重金属污染程度监测指标,但应用到实际养殖水体尚须进一步研究。

In order to understand potential of antioxidant enzyme in Crassostrea rivularis as a biomarker of heavy metal pollution in mariculture water, effects of metal ions Cu^2＋, Pb^2＋ and Zn^2＋ on the activity of SOD in gills and digestive glands of C.rivularis were observed under the laboratory condition. The results demonstrated that Cu^2＋, Pb^2＋ and Zn^2＋ all of them induced the changes in SOD activity both in gills and digestive glands of oysters, but the changes in digestive glands was larger than those in gills under the present of same metals due to the difference in structure and function between them. The dose-effect curves of the activity of SOD induced by the different concentrations of pb^2＋and Zn^2＋ both in gills and digestive glands were parabola. But for Cu^2＋, it didn＇t accord with parabola in gills, and did in digestive glands. Based on the induction multiples of the activity of SOD in soft tissues of C. rivularis under the present of low concentration of metals, the order of the toxicity of the three metals to C. rivularis was Cu^2＋〉pb^2＋〉Zn^2＋. The activity of SOD in digestive glands of C. rivularis could be used as a biomarker of monitoring heavy metals pollution in water, but the further studies should be carried out in the future.