基于IBR模型研究磷化工区溪流水体对斑马鱼的毒性效应

Toxicity Effects of Stream Water in Phosphorus Chemical Industrial Area on Zebrafish Based on IBR Model

为评价磷化工区溪流水体的潜在生态风险及其对水生动物的毒性效应,选择磷化工区溪流水体对斑马鱼进行28 d暴露实验,测定不同暴露时间下斑马鱼肝脏、鳃组织中超氧化物歧化酶(superoxide dismutase,SOD)、过氧化氢酶(catalase,CAT)、过氧化物酶(peroxidase,POD)活性及丙二醛(malondialdehyde,MDA)、谷胱甘肽(glutathione,GSH)含量,并运用整合生物标志物响应指数(integrated biomarker response,IBR)综合评价该溪流水体对斑马鱼的毒性效应。结果表明,在磷化工区溪流水体胁迫下,斑马鱼肝脏、鳃组织中SOD、CAT和POD活性随时间变化均呈现先升高后降低的趋势,且在第7天时,除肝脏POD酶活性变化不显著外(P>0.05),其他酶活性均达峰值(P<0.01);肝脏组织中MDA、GSH含量呈现降低趋势,其中,MDA含量在第14天时显著低于对照组水平(P<0.01);GSH含量在第21天时显著低于对照组水平(P<0.01);鳃组织中MDA、GSH含量则呈现先升高后降低的趋势,且在第7天时显著高于对照组水平(P<0.05),随着暴露时间的延长,除鳃组织GSH含量在第28天显著低于对照组外(P<0.05),其他时间点鳃组织MDA、GSH含量变化均不显著(P>0.05)。运用IBR方法进行计算发现,磷化工区溪流水体对斑马鱼肝脏、鳃组织的毒性效应呈现显著的时间效应;总体上肝脏IBR值大于鳃,表明磷化工区溪流水体对斑马鱼肝脏的影响高于鳃。磷化工区溪流水体具有一定生物毒性,磷化工污染的水生生态风险应受到关注。

In order to assess the potential ecological risk of stream water in phosphorus chemical industrial area and its toxicity effect on aquatic animals,zebrafish(Danio rerio)were exposed to stream water for 28 days.The activities of superoxide dismutase(SOD),catalase(CAT),peroxidase(POD)were not only measured in the zebrafish liver and gill in different exposure time,but also the content of malondialdehyde(MDA)and glutathione(GSH).The integrated biomarker response(IBR)method was then applied to evaluate the toxicity effect of stream water on zebrafish.Results showed that:(1)under the stress of stream water in phosphorus chemical industrial area,the activities of SOD,CAT and POD in zebrafish liver and gill increased first and then decreased with time;on day 7,the activities of other enzymes reached the maximum values(P<0.01),except that there was no significant change in liver POD enzyme activity(P>0.05);(2)the contents of both MDA and GSH in liver tissue decreased,and particularly the MDA content was significantly lower compared to the control group on day 14(P<0.01),while the GSH level was significantly lower than that of the control group on day 21(P<0.01);(3)there presented a tendency of increasing first and then decreasing in the MDA and GSH contents of gill tissue;on day 7,they were in a significantly higher level than the control group(P<0.05);however,with the extension of exposure time,the content of GSH in gill tissue on day 28 became lower than the control group(P<0.05);at other time points,the contents of MDA and GSH in gill tissue did not change significantly(P>0.05).On another hand,the IBR index values revealed that stream water had significant temporal toxicity effects on zebrafish liver and gill tissues,and the liver IBR value was greater than that of gill.All of this indicated that the stream water in phosphorus chemical industrial area had a certain biological toxicity.Therefore,particular attention should be paid to the aquatic ecological risk of phosphorus chemical pollution.