Zebrafishlab, Veterinary Physiology and Biochemistry, Department of Veterinary Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium.
Department of Environmental Engineering, Technical University of Denmark, Miljoevej 113, 2800 Kgs. Lyngby, Denmark.
Chemosphere. 2015 Nov;139:9-17. doi: 10.1016/j.chemosphere.2015.05.041. Epub 2015 May 27.
High throughput testing according to the Fish Embryo Acute Toxicity (FET) test (OECD Testing Guideline 236) is usually conducted in well plates. In the case of hydrophobic test substances, sorptive and evaporative losses often result in declining and poorly controlled exposure conditions. Therefore, our objective was to improve exposure conditions in FET tests by evaluating a passive dosing format using silicone O-rings in standard 24-well polystyrene plates. We exposed zebrafish embryos to a series of phenanthrene concentrations until 120h post fertilization (hpf), and obtained a linear dilution series. We report effect values for both mortality and sublethal morphological effects based on (1) measured exposure concentrations, (2) (lipid normalized) body residues and (3) chemical activity. The LC50 for 120hpf was 310μg/L, CBR50 (critical body residue) was 2.72mmol/kg fresh wt and La50 (lethal chemical activity) was 0.047. All values were within ranges expected for baseline toxicity. Impaired swim bladder inflation was the most pronounced morphological effect and swimming activity was reduced in all exposure concentrations. Further analysis showed that the effect on swimming activity was not attributed to impaired swim bladder inflation, but rather to baseline toxicity. We conclude that silicone O-rings (1) produce a linear dilution series of phenanthrene in the 120hpf FET test, (2) generate and maintain aqueous concentrations for reliable determination of effect concentrations, and allow for obtaining mechanistic toxicity information, and (3) cause no toxicity, demonstrating its potential as an extension of the FET test when testing hydrophobic chemicals.
高通量测试根据鱼类胚胎急性毒性（FET）测试（OECD 测试指南 236）通常在微孔板中进行。对于疏水性测试物质，吸附和蒸发损失通常会导致暴露条件下降和难以控制。因此，我们的目标是通过评估在标准 24 孔聚苯乙烯板中使用硅氧烷 O 形环的被动给药格式来改善 FET 测试中的暴露条件。我们将斑马鱼胚胎暴露于一系列菲浓度下，直到受精后 120 小时（hpf），并获得线性稀释系列。我们根据（1）测量的暴露浓度、（2）（脂质归一化）体残留物和（3）化学活性报告死亡率和亚致死形态效应的效应值。120hpf 的 LC50 为 310μg/L，CBR50（临界体残留物）为 2.72mmol/kg 鲜重，La50（致死化学活性）为 0.047。所有值均在基线毒性的预期范围内。受损的鳔充气是最明显的形态效应，所有暴露浓度下的游泳活动均减少。进一步的分析表明，游泳活动的影响不是归因于受损的鳔充气，而是归因于基线毒性。我们得出结论，硅氧烷 O 形环（1）在 120hpf FET 测试中产生菲的线性稀释系列，（2）产生和维持水相浓度，以可靠地确定效应浓度，并允许获得机制毒性信息，以及（3）不会引起毒性，证明其在测试疏水性化学品时作为 FET 测试的扩展具有潜力。
