Dipartimento di Morfologia Umana e Biologia Applicata, sezione Biologia e Genetica, Università di Pisa, Via A. Volta 4, 56126 Pisa, Italy.
Aquat Toxicol. 2010 Oct 1;100(1):75-83. doi: 10.1016/j.aquatox.2010.07.009. Epub 2010 Jul 13.
The freshwater painter's mussel (Unio pictorum) was used as sentinel species to assess the chemical disturbance in an Italian river (the river Cecina) characterized by elevated levels of trace metals of both natural and anthropogenic origin. Organisms were transplanted for 4 weeks in different locations of the river basin and the bioaccumulation of metals was integrated with a wide battery of biomarkers consisting of oxidative, genotoxic and lysosomal responses. Such parameters included the levels of individual antioxidants (catalase, glutathione-S-transferases, glutathione reductase, Se-dependent and Se-independent glutathione peroxidases, total glutathione), the total oxyradical scavenging capacity (TOSC), metallothionein-like proteins, the assessment of DNA integrity, chromosomal damages and lysosomal membrane stability. Elevated levels of several metals were measured in sediments, but the relatively low tissue concentrations suggested a moderate bioaccumulation, possibly due to a high excretion efficiency, of U. pictorum and/or to a limited bioavailability of these elements, partly deriving from erosion of bedrocks. Among antioxidant responses, those based on glutathione metabolism and the activity of catalase were mostly affected in bivalves showing a significant accumulation of arsenic, mercury and/or nickel. In these specimens, the content of glutathione and the activities of glutathione reductase and glutathione peroxidases (H2O2) were respectively 9-, 6- and 4-fold lower than in controls, while a 3-fold increase was observed for catalase. Despite some differences in the response of individual antioxidants, a significant reduction of the capability to neutralize peroxyl radicals was observed in bivalves caged in all the impacted sites of the river basin; these organisms also exhibited a significant impairment at the DNA, chromosomal and lysosomal levels. Considering the mild contamination gradient in the investigated area, the overall results suggested that some oxidative biomarkers, as well as those evaluating chromosomal and cell damages, are highly sensitive and could be profitably applied to caged painter's mussels for environmental quality assessment in freshwater.
淡水画家贻贝（Unio pictorum）被用作指示物种，以评估意大利河流（塞奇纳河）的化学干扰，该河流以天然和人为来源的痕量金属含量高为特征。将贻贝移植到河流流域的不同地点 4 周，并将金属的生物累积与包括氧化、遗传毒性和溶酶体反应在内的广泛生物标志物进行整合。这些参数包括个体抗氧化剂（过氧化氢酶、谷胱甘肽 S-转移酶、谷胱甘肽还原酶、硒依赖和硒独立谷胱甘肽过氧化物酶、总谷胱甘肽）、总氧自由基清除能力（TOSC）、金属硫蛋白样蛋白、DNA 完整性评估、染色体损伤和溶酶体膜稳定性的水平。沉积物中测量到几种金属的含量升高，但相对较低的组织浓度表明 U. pictorum 的生物积累程度适中，这可能是由于其排泄效率较高，或者这些元素的生物利用度有限，部分原因是基岩的侵蚀。在抗氧化反应中，基于谷胱甘肽代谢和过氧化氢酶活性的反应在双壳类动物中受到的影响最大，这些双壳类动物中砷、汞和/或镍的积累量显著增加。在这些标本中，谷胱甘肽的含量以及谷胱甘肽还原酶和谷胱甘肽过氧化物酶（H2O2）的活性分别比对照组低 9 倍、6 倍和 4 倍，而过氧化氢酶的活性则增加了 3 倍。尽管个别抗氧化剂的反应存在一些差异，但在河流流域所有受影响地点的笼子中饲养的贻贝中，其清除过氧自由基的能力显著降低；这些生物在 DNA、染色体和溶酶体水平上也表现出明显的损伤。考虑到研究区域内的轻度污染梯度，总体结果表明，一些氧化生物标志物以及评估染色体和细胞损伤的生物标志物非常敏感，可以应用于淡水笼养画家贻贝，用于环境质量评估。
