铅和萘联合暴露对斑马鱼胚胎发育的影响

Effects of combined exposure to lead and naphthalene on development of zebrafish embryos

[目的]研究铅和萘单独及联合暴露对斑马鱼胚胎发育的影响。[方法]将500个斑马鱼胚胎随机分为10组,以铅(0、12、48μmol/L)和萘(0、5、20μmol/L)单独及联合(12μmol/L铅+5μmol/L萘、12μmol/L铅+20μmol/L萘、48μmol/L铅+5μmol/L萘、48μmol/L铅+20μmol/L萘)对斑马鱼胚胎进行染毒,染毒时间为受精后8 h至受精后144 h。观察、记录并统计胚胎的死亡率、孵化率和畸形率,通过Etho Vision XT软件来获取并分析斑马鱼胚胎和幼鱼的行为,包括自主抽动、心率以及幼鱼应对光周期刺激的游动速度。[结果]与对照组相比,48μmol/L铅暴露组和20μmol/L萘暴露组的死亡率明显升高(P<0.05),孵化率明显下降(P<0.05),20μmol/L萘暴露组的畸形率明显升高(P<0.05)。与同浓度的铅和萘单独暴露组相比,12μmol/L铅+5μmol/L萘联合暴露组和48μmol/L铅+20μmol/L萘联合暴露组的死亡率明显升高(P<0.05),48μmol/L铅+20μmol/L萘联合暴露组的孵化率明显下降(P<0.05),12μmol/L铅+20μmol/L萘、48μmol/L铅+5μmol/L萘、48μmol/L铅+20μmol/L萘联合暴露组的畸形率均明显升高(P<0.05)。铅和萘联合暴露对胚胎的死亡率(F=2.863,P<0.05)、孵化率(F=4.474,P<0.05)和畸形率(F=5.084,P<0.05)的影响存在交互作用。与空白对照组相比,48μmol/L铅暴露组幼鱼的游动速度在第一黑暗期和第二、三明亮期明显下降(P<0.05);与丙酮对照组相比,20μmol/L萘暴露组幼鱼的游动速度在每一时期都明显下降(P<0.05)。与同浓度的铅和萘单独暴露组相比,48μmol/L铅+20μmol/L萘联合暴露组幼鱼的游动速度在第一黑暗期明显下降(P<0.05),铅和萘联合暴露对幼鱼游动速度的影响存在交互作用(F=4.493,P<0.05)。[结论]铅和萘均可影响斑马鱼胚胎的发育,并且具有一定的神经发育毒性,而二者联合暴露对斑马鱼胚胎死亡率、孵化率、畸形率和斑马鱼幼鱼神经行为的影响有明显的交互作用。

[Objective] To study the effects of individual and combined exposure to lead and naphthalene on the development of zebrafish embryos.[Methods] Zebrafish embryos（n=500） were randomly divided into 10 groups.Lead（0,12,and 48 μmol/L） and naphthalene（0,5,and 20 μmol/L） were administered individually or combined to zebrafish embryos from 8 h post fertilization until 144 h post fertilization.Mortality,hatchability,and malformation were observed,recorded,and calculated.Spontaneous movement,heart beats,and swimming speeds in response to photoperiod stimulation in larval zebrafish were recorded and analyzed.[Results] Compared to the control groups,exposure to 48 μmol/L lead or 20 μmol/L naphthalene caused a significant increase in mortality and a significant decrease in hatchability（P〈0.05）,and exposure to 20 μmol/L naphthalene caused a significant increase in malformation（P〈0.05）.Compared to individual exposure at the same concentration： combined exposure to 12 μmol/L lead＋5 μmol/L naphthalene or 48 μmol/L lead＋20 μmol/L naphthalene caused a significant increase in mortality; combined exposure to 48 μmol/L lead＋20 μmol/L naphthalene caused a significant decrease in hatchability（P〈0.05）; combined exposure to 12 μmol/L lead＋20 μmol/L naphthalene,48 μmol/L lead＋5 μmol/L naphthalene,or 48 μmol/L lead＋20 μmol/L naphthalene caused a significant increase in malformation（P〈0.05）.There were interactions between lead and naphthalene on mortality（F=2.863,P〈0.05）,hatchability（F=4.474,P〈0.05）,and malformation（F=5.084,P〈0.05）.Compared to the blank control group,the larval zebrafish＇s swimming speed was decreased after individual exposure to 48 μmol/L lead at the first dark period and the second and third light periods（P〈0.05）.Compared to the acetone control group,the swimming speed was decreased after individual exposure to 20 μmol/L naphthalene at all periods（P〈0.05）.Compared to individual exposure at the same concentration,the larval zebrafish＇s swimming speed was decreased after combined exposure to 48 μmol/L lead＋20 μmol/L naphthalene at the first dark period（P〈0.05）.There was an interaction between lead and naphthalene on swimming speed（F=4.493,P〈0.05）.[Conclusion] Exposure to lead and naphthalene could impair the development of zebrafish embryos and cause developmental neurotoxicity.Lead and naphthalene have interaction effects on the mortality,hatchability,and malformation of zebrafish embryos and neurobehavior of zebrafish larvae.