三甲基氯化锡对斑马鱼(Danio rerio)生理生化特性的影响

Effects of Trimethyltin Chloride on Physiological and Biochemistrical Characteristics of Danio rerio

为初步探讨三甲基氯化锡(trimethyltin chloride,TMT)对鱼类的毒性效应以及评价环境中TMT的安全性,采用静态鱼类急性毒性试验法测定了TMT对斑马鱼(Danio rerio)生理生化指标的影响;参考TMT的96h-LC50值,设定3个浓度(0.39、0.78和1.17mg·L-1)处理斑马鱼,测定了72h内鳃Na+,K+-ATPase、头部乙酰胆碱酯酶(AchE)和肌肉超氧化物歧化酶(SOD)的活性变化。结果表明,TMT对斑马鱼的96h-LC50值为2.35mg·L-1,安全浓度为0.23mg·L-1。TMT对斑马鱼鳃Na+,K+-AT-Pase有明显的抑制作用。当TMT浓度≥0.78mg·L-1时酶活性被完全抑制(抑制率>32%),低浓度组0.39mg·L-1酶活性先表现为抑制,24h后有恢复到对照组水平的趋势。TMT对斑马鱼头部AchE活性表现为抑制,随着暴露时间的延长和药物浓度的增加,酶活性抑制增强。由于鱼脑AchE的高波动性,实验中只有最高浓度组1.17mg·L-1的鱼受到明显的抑制(p<0.05)。TMT对斑马鱼肌肉SOD活性总体表现为先激活后下降趋势,TMT浓度越高酶活性激活越快,下降也越快,其中0.39、0.78和1.17mg·L-1组活性分别在48、24和12h激活到最大,SOD活性分别为对照组的153%、145%和153%。以上结果表明,TMT对斑马鱼属于高毒。斑马鱼鳃Na+,K+-ATPase是三甲基氯化锡的作用标靶,可以作为TMT对斑马鱼毒性效应的敏感指标。

To explore the toxicity of trimethyltin chloride（TMT） on fish,effects of TMT on physiological and biochemistrical characteristics of Danio rerio were measured using the acute toxicity test.According to the 96 h-LC50 value of TMT,three different concentration groups（0.39,0.78,1.17 mg·L-1） were set.The activity changes of Na＋,K＋-ATPase in the gills,AchE in the head and SOD in the muscle were detected in 72 hours.The results showed that 96 h-LC50 value of TMT on Danio rerio was 2.35 mg·L-1 and the safe concentration was 0.23 mg·L-1.There was a significant inhibition to Na＋,K＋-ATPase in the gills.When TMT concentration was more than 0.78 mg·L-1,the enzyme activity was virtually inhibited（the inhibition ratio32%）.Na＋,K＋-ATPase activity was inhibited in the low concentration（0.39 mg·L-1） and had a trend of recovery to the level of control group after 24 h.TMT showed an inhibitor to AchE in the head of Danio rerio,which would increased with the increasing of the time and medicine density.Because of the high motion of AchE in the head,only Danio rerio in the most concentration group（1.17 mg·L-1） was significantly inhibited（p0.05）.SOD activity in muscle of Danio rerio showed that the trend of increasing first,and then decreased.The higher TMT concentration was,the faster the enzyme activity activated and declined.Among all groups,the groups of 0.39,0.78 and 1.17 mg·L-1 would get to the most inhibition effect which were 153%,145% and 153% times of control group at 48,24 and 12 h,respectively.All results indicated that TMT was high toxicity to Danio rerio.Na＋,K＋-ATPase in the gills was the important target of TMT.