硫氰酸钠对斑马鱼毒性的评价

Assessment of NaSCN Toxicity on Brachydanio rerio

为了研究植物性饲料代谢产生的中间产物硫氰酸钠(NaSCN)对水生生物的毒性效应,首先将斑马鱼(Brachydanio rerio)暴露于NaSCN的8个浓度组中进行96h-LC50急性毒性试验,测得其半致死浓度(96h-LC50)为403mg.L-1。再以安全浓度(1/10LC50)为基准,等对数设置3个质量浓度22.7、40.3、71.7mg.L-1的染毒组和一个对照组(0mg.L-1)进行96h半静水式毒性试验,测定斑马鱼头部组织乙酰胆碱酯酶(AChE)和Na+/K+-ATPase的活性、躯干组织MDA的含量。将实验数据进行ANOVA分析处理后,结果表明,不同NaSCN浓度处理组与对照相比,AChE活性无显著差异。71.7mg.L-1浓度处理组与对照相比,Na+/K+-ATPase的活性和MDA含量存在极显著差异。且MDA含量与NaSCN染毒浓度间存在明显的剂量-效应关系。实验结果表明NaSCN对斑马鱼的毒性机制可能是引起线粒体功能的失调。MDA能够作为一种有效的生物标志物对NaSCN引起的毒性做出评价。

To study the toxic effects of NaSCN on the aquatic specials,Brachydanio rerio were exposed to NaSCN of eight different concentrations for 96 h-LC50 measurement.It shows that the 96 h-LC50 is 403 mg·L-1,thus the safe concentration（1/10 LC50） is 40.3 mg·L-1.Next,the safe concentration was set as the standard,three NaSCN concentrations（22.7,40.3,71.7 mg·L-1） were confected using the same logarithmic distance with a control group（0 mg·L-1）,and 96 hours＇ acute toxicity test was carried out.In the meantime,the activities of AChE and Na＋/K＋-ATPase in B.rerio brain tissue were measured;the MDA contents in B.rerio body tissue were also measured.The results of ANOVA test show that the AChE activities of NaSCN exposure groups were not significantly different compared with the control group.While the Na＋/K＋-ATPase activities and the MDA contents of 71.7 mg·L-1 group were significantly different（p =0.01） compared with the control group.The contents of MDA and the concentrations of NaSCN showed obvious dose-response relation.Thus,it was deduced that the toxicity mechanism of NaSCN to B.rerio was mainly resulting from the dysfunction of mitochondrion.And MDA content could be used as an effective biomarker for toxicity assessment of NaSCN to B.rerio.