全氟辛酸PFOA对斑马鱼生物毒性效应的影响研究

Effect of PFOA on the biologic toxicity in zebrafish

为进一步了解PFOA对水生生物的毒性效应,采用室内暴露实验方法,将斑马鱼暴露于5,15,45,135 mg/L的PFOA实验液中,实验周期15 d。结果表明,PFOA可以引起斑马鱼氧化应激反应,ROS、MDA含量变化与SOD活力变化呈现“相反”趋势。PFOA对斑马鱼体内ROS具有诱导作用,且高浓度的PFOA对ROS诱导作用更显著。MDA含量变化与ROS一致,均在实验暴露前9 d被诱导,暴露12 d后与空白组无显著差异。而SOD活力与两者相反,在暴露前9 d表现为先抑制后诱导,暴露12 d以后,低暴露组SOD活力与空白组无显著差异,但高暴露组SOD活力仍受到显著抑制。随着暴露时间的增长,PFOA对斑马鱼头部AchE活性表现为先诱导后抑制的作用,对LDH活性表现为抑制、诱导、抑制的作用。上述研究结果表明,斑马鱼对PFOA的氧化应激反应有明显的时间-效应和剂量-效应关系,并能导致细胞出现能量代谢障碍或者出现细胞损伤,但在斑马鱼可承受范围之内。PFOA具有神经毒性,通过诱导斑马鱼AchE活性,使神经突触间隙中乙酰胆碱数量减少,抑制兴奋传递。

In order to have a better understanding of the toxicity effect of PFOA to aquatic organisms,indoor exposure test were conducted.Zebrafish was exposed to PFOA at different concentrations of 5,15,45 and 135 mg/L,respectively.After 15 d,the results showed that PFOA can induced the oxidative stress reaction of zebrafish.The change of SOD activity was opposed to the content change of ROS and MDA.The ROS was induced by PFOA,and higher concentrations induce more significantly effect.The results are in good agreement with the ROS content and MDA content.The ROS and MOD content were significantly induced for 9 d.After exposure for 12 d,no significant differences were found between the experimental groups and control groups.But the activity of SOD was increased firstly and then decreased.After exposure for 12 d,there was no significant differences between control groups and lower concentration groups.The activity of SOD at higher concentrations groups decreased markedly.The activity of AchE on zebrafish head was increased firstly and then decreased.The activity of LDH on zebrafish muscle tissue was decreased firstly and then increased,but was decreased finally.All the results indicate that there is a time-effect relationship and concentration-effect relationship between PFOA and the zebrafish oxidative stress reaction,causes energy metabolism disorder or cell damage,and this effect can be repaired by zebrafish.PFOA has neurotoxicity,the amount of acetylcholine in synaptic space was reduced and excitation transmission was inhibited,because of the activity of AchE in zebrafish was increased.