nano-ZnO对斑马鱼鱼鳔发育毒性效应研究

根据鱼鳔发育的不同阶段,从受精后0 h(0 hours post fertilization, 0 hpf)开始对5个发育阶段(0 hpf～孵化前、0～120 hpf、0～168 hpf、孵化后～120 hpf、120～168 hpf)的斑马鱼进行nano-ZnO暴露实验,研究不同浓度的nano-ZnO对斑马鱼鱼鳔的影响.结果表明,nano-ZnO悬浮液中溶解的Zn~(2+)不是导致斑马鱼死亡和鱼鳔缺损的唯一或主要原因.nano-ZnO暴露浓度越高,斑马鱼的死亡率和鱼鳔缺损率越高,存在剂量-效应关系.15 mg·L~(-1) nano-ZnO可造成90%的斑马鱼鱼鳔缺损和死亡,10 mg·L~(-1) nano-ZnO可导致斑马鱼鱼鳔面积缩小70%.斑马鱼鱼鳔早期发育阶段(0～168 hpf)对nano-ZnO敏感度大小为:出芽阶段(0 hpf～孵化前)充气阶段(孵化后～120 hpf)充气完成阶段(120～168 hpf).斑马鱼鱼鳔的发育面积和发育时间也受nano-ZnO暴露染毒的影响而发生变化.斑马鱼死亡率和鱼鳔缺损率(鱼鳔发育)之间存在相关性(r=0.978,p0.01).这表明斑马鱼鱼鳔的发育缺损是造成斑马鱼胚胎死亡的主要原因之一,但nano-ZnO对斑马鱼鱼鳔的影响机理,尤其是对鱼鳔出芽阶段和充气阶段的致毒机理需要进一步研究.

Study on developmental toxic effects on the swim bladder of zebrafish exposed to nano-ZnO

The toxic effects of nano-ZnO with different exposure concentrations on the swim bladder of zebrafish at different exposure periods were studied according to the developmental stage of the swim bladder, which included 0-hour post fertilization (hpf)-before hatching, 0~120 hpf, 0~168 hpf, after hatching-120 hpf, and 120~168 hpf. The results showed that the dissolution of Zn²⁺ from nano-ZnO suspension was not the only or primary reason for the mortality of zebrafish and damage to the swim bladder. A dose-response relationship was observed that damage rates of swim bladder or mortalities of zebrafish increased with the increasing nano-ZnO concentrations. Exposure to 15 mg·L^-1 nano-ZnO caused the mortality of zebrafish and damage to the swim bladder (90% of control), while exposure to 10 mg·L^-1 nano-ZnO led to a reduction in the area of the swim bladder (70% of control). The sensitivity of early developmental stage (0~168 hpf) of zebrafish to nano-ZnO had the following order:budding stage (0 hpf-before hatching) > inflating stage (after hatching-120 hpf) > inflation complete stage (120~168 hpf). The developmental area and time of swim bladder were also affected by nano-ZnO exposure. There was a significant correlation between the damage rate to swim bladder and the mortality of zebrafish (r=0.978, p < 0.01), indicating that the damage to developing swim bladder was one of the main reason for the embryonic death of zebrafish after exposure to nano-ZnO. However, the toxicological mechanism of nano-ZnO on the swim bladder of zebrafish, especially for the budding stage and inflating stages, is unknown and should be further investigated.