圆田螺保护酶分子在大运河污染评价中的应用

Application of Protective Enzyme Molecular of Cipangopaludina cahayensis in Jing-Hang Canal Pollution Assessment

[目的]研究以中华圆田螺(Cipangopaludina cahayensis)保护酶作为京杭大运河不同污染程度环境监测的可行性。[方法]通过测定螺内脏团中超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)的活性,比较室内模拟法、样点笼内放养法和直接采样法测定保护酶分子标志物活性评价大运河污染方法的优劣。[结果]中华圆田螺组织抗氧化保护酶系统的SOD、POD、CAT活性是指示污染的敏感指标。CAT活性在污染环境中被抑制,且在临界范围内随着污染毒性作用的加强,抑制作用也加强。POD活性在污染环境中被激活,但各时间段的增幅变化却不尽相同。SOD的变化不稳定,它在30 d暴露后的降低表明其较适合作为短时间的检测指标。[结论]中华圆田螺保护酶作为京杭大运河不同污染程度环境监测的分子标志物是可行的,样点笼内放养测定保护酶分子标志物活性评价法最优,直接采样测定保护酶活性法不可取。

[ Objective ] The research aimed to study if it was proper that protective enzyme molecular biomarkers of Cipangopaludina cahayensis was applied in the pollution assessment in Jing-Hang Canal. [ Method] Superoxide dismatase （SOD）, peroxidase（POD） and catalase （CAT） in the innards of Cipangopaludina cahayensis were measured in different plots of Jing-Hang Canal to study the changes of these antioxidant parameters under environmental variation. The methods measuring SOD, POD and CAT activity by laboratory simulation, cage stocking and direct sampling from canal were compared. [ Result ] Antioxidant defense components （SOD , POD and CAT） in Cipangopaludina cahayens/s were sensitive indices for pollution. Within the threshold, catalase activity was inhibited along with the increasing of pollutant concentra- tion. POD presehted an activity, but the amplitudes were different. SOD presented a unsteady activity, and activity decrease of SOD after exposure for 30 d indicated that it was useful as biomarker in short term. [ Conclusion] Application of protective enzyme molecular biomarkers of Cipangopaludina cahayensis pollution assessment in Jing-Hang canal was proper. Cage stocking method was the optimum, and direct sampling was improper.