Ternopil Volodymyr Hnatiuk National Pedagogical University, Ternopil, Ukraine.
Nature Research Centre, Vilnius, Lithuania.
Ecotoxicology. 2022 Nov;31(9):1369-1381. doi: 10.1007/s10646-022-02594-8. Epub 2022 Oct 8.
Even though bivalve molluscs are recognized as bioindicators of freshwater quality, their responses to multiple stressors are unpredictable. This study aims to elucidate the inter-population peculiarities of the effect in the sub-chronic environmentally relevant exposure to novel contaminants. The specimens of Unio tumidus from reference (Pr) and contaminated (Ct) areas were treated with ibuprofen (IBU, 0.8 µg L), microplastic (MP, 1.0 mg L, size 0.1-0.5 mm), or their combination (Mix) for 14 days. Untreated mussels (PrC- and CtC-groups) served as controls. The PrC-group had higher levels of antioxidants Mn-SOD, Cu,Zn-SOD, catalase, and cholinesterase (AChE) as well as lesser levels of oxidative lesions (TBARS and protein carbonyls) in digestive glands, indicating lower environmental impact than in the CtC-group. However, lysosomal stability was similar in both control groups. Among antioxidants, Mn-SOD activity was affected most prominently, increasing in all exposed Ct-groups. TBARS level was increased only in PrMP-group compared to responsive control. IBU and Mix enhanced protein carbonyl concentration in the Pr-groups, and decreased it in the Ct-groups. AChE was induced in the CtIBU- and PrMix-groups, and lysosomal integrity increased in the CtIBU and CtMix-groups. Discriminant analyses indicated lesser differences between Pr-groups, demonstrating lower cumulative stress compared to Ct-groups. Generally, the most remarkable response was revealed in the CtIBU-group, and distortion of individual effects was established in combined exposures. The qualification of stress-neutral and stress-positive populations was proposed for Pr- and Ct-populations correspondingly. Inter-site peculiarities must be taken into consideration when the environmental impact of MP and pharmaceuticals is evaluated.
尽管双壳类软体动物被认为是淡水水质的生物指标，但它们对多种胁迫的反应是不可预测的。本研究旨在阐明在亚慢性环境相关的新型污染物暴露下，种群间的这种效应的特点。取自参照区（Pr）和污染区（Ct）的三角帆蚌（Unio tumidus）标本，用布洛芬（IBU，0.8μg/L）、微塑料（MP，1.0mg/L，粒径 0.1-0.5mm）或其混合物（Mix）处理 14 天。未处理的贻贝（PrC-和 CtC-组）作为对照。PrC 组的抗氧化酶 Mn-SOD、Cu，Zn-SOD、过氧化氢酶和胆碱酯酶（AChE）水平较高，而消化腺中的氧化损伤（TBARS 和蛋白质羰基）水平较低，表明环境影响较小，而 CtC-组则相反。然而，两组对照的溶酶体稳定性相似。在抗氧化剂中，Mn-SOD 活性受影响最大，所有暴露于 Ct 组的活性均增加。与反应性对照相比，只有 PrMP 组的 TBARS 水平升高。IBU 和 Mix 增加了 Pr 组的蛋白质羰基浓度，降低了 Ct 组的浓度。CtIBU-和 PrMix-组的 AChE 被诱导，CtIBU 和 CtMix-组的溶酶体完整性增加。判别分析表明，Pr 组之间的差异较小，表明与 Ct 组相比，累积压力较小。一般来说，CtIBU 组的反应最为显著，在联合暴露下，个体效应的扭曲得以确立。相应地，提出了将压力中和和压力阳性种群用于 Pr 和 Ct 种群的资格。在评估微塑料和药物的环境影响时，必须考虑到站点间的特点。
