Post-Graduate Program of Ecology and Natural Resources, Department of Ecology and Evolutionary Biology, Federal University of São Carlos, Rodovia Washington Luis, km 235, CEP 13565-905 São Carlos, SP, Brazil.
Special Bureau for the Environment, Federal University of São Carlos, Rodovia Washington Luis, km 235, CEP 13565-905, São Carlos, SP, Brazil.
Harmful Algae. 2016 May;55:150-162. doi: 10.1016/j.hal.2016.03.005. Epub 2016 Mar 17.
The specificity of cholinesterase (ChE) activity to detect the presence of anatoxin-a(s) and sublethal effects of a 7-day exposure to Anabaena spiroides extract containing anatoxin-a(s) were assessed in two freshwater cladoceran species. Activities of ChE of both Pseudosida ramosa and Daphnia magna can be used to indicate the presence of the neurotoxin anatoxin-a(s), but not for the hepatotoxic microcystin. Activity of ChE of P. ramosa, however, performed better as a biomarker of exposure to A. spiroides than that of D. magna. Furthermore, sublethal exposure to A. spiroides extract significantly inhibited the ChE activity in P. ramosa and negatively affected both individual and population endpoints. For D. magna, the inhibition of ChE activity was not related to effects at higher levels of biological organization, since no direct effect was recorded on the individual and population endpoints. The activity of ChE in P. ramosa also proved to be a good predictor of chronic effects of the A. spiroides extract at higher levels of biological organization, since 48-h ChE inhibition was linked to the sublethal effects on the individual and population. These relationships could not be established for D. magna. Since relationships between the effects of A. spiroides extract at different levels of biological organization were species-specific, it can be concluded that the choice of test organism interferes with the accuracy of the environment risk assessment of this neurotoxin and, hence, the use of native species is recommended for its assessment.
在两种淡水枝角类动物中评估了胆碱酯酶 (ChE) 活性的特异性，以检测anatoxin-a(s) 的存在和暴露于含有anatoxin-a(s) 的螺旋鱼腥藻提取物 7 天的亚致死效应。两种伪鱼腥藻和大型蚤的 ChE 活性均可用于指示神经毒素 anatoxin-a(s) 的存在，但不能指示肝毒素微囊藻毒素。然而，与大型蚤相比，P. ramosa 的 ChE 活性更能作为暴露于螺旋鱼腥藻的生物标志物。此外，亚致死暴露于螺旋鱼腥藻提取物会显著抑制 P. ramosa 的 ChE 活性，并对个体和种群终点产生负面影响。对于大型蚤，ChE 活性的抑制与更高水平的生物组织中的效应无关，因为在个体和种群终点没有记录到直接效应。P. ramosa 中的 ChE 活性也被证明是螺旋鱼腥藻提取物在更高水平的生物组织中慢性效应的良好预测因子，因为 48 小时 ChE 抑制与个体和种群的亚致死效应相关。对于大型蚤，无法建立这些关系。由于不同水平的生物组织中螺旋鱼腥藻提取物的效应之间的关系是特定于物种的，因此可以得出结论，测试生物的选择会干扰对这种神经毒素的环境风险评估的准确性，因此建议使用本地物种进行评估。
