Multicenter Program in Postgraduate in Biochemistry and Molecular Biology - PMBqBM, Santa Catarina State University, Lages, 88520-000, Brazil; Centre for Marine and Environmental Research - CIMA, University of Algarve, Campus de Gambelas, Faro, 8000-139, Portugal.
Laboratory of Biomarkers of Aquatic Contamination and Immunochemistry - LABCAI, Federal University of Santa Catarina, Florianópolis, 88034-257, Brazil.
Chemosphere. 2023 Oct;337:139288. doi: 10.1016/j.chemosphere.2023.139288. Epub 2023 Jun 20.
Pollutant exposure is considered an important factor responsible for the decline in marine biodiversity of Latin American coastal ecosystems. This threat has been detected in an estuarine system in southern Brazil, which prompted an investigation into the long-term biological effects of a chronic metal contamination on resident oysters from the Laguna Estuarine System (LES). Here, we present the species- and size-specific variations of biomarker responses (catalase, glucose-6-phosphate dehydrogenase, glutathione S-transferase, and protein carbonylation) in the gills and digestive gland of Crassostrea gigas and Crassostrea gasar. In parallel, concentrations of eight metals (Al, Cd, Cr, Cu, Fe, Mn, Pb, Zn) in soft tissues were measured. Our analyses revealed that the metal levels exhibited decreasing order in both species: Zn > Fe > Al > Cu > Mn > Cd. Except for Cu and Al, metal concentrations did not differ between oyster species. Biomarker results highlighted that C. gasar presented higher antioxidant responses, whereas C. gigas showed increased biotransformation upon exposure to LES pollutants, which varied according to the tissue. However, C. gasar showed a significant higher content of protein carbonylation but was not related to metals. In our research approach, the observation of metals presence and biomarkers-related responses are considered biologically relevant from an ecotoxicological perspective and serve as a baseline for future pollution studies in estuaries of Latin America. Finally, we recommend adopting a suite of biomarkers in both C. gasar and C. gigas, regardless their size and weight, as sentinel organisms in future regional biomonitoring studies in southern Brazil.
污染物暴露被认为是导致拉丁美洲沿海生态系统海洋生物多样性下降的一个重要因素。在巴西南部的一个河口系统中检测到了这种威胁,这促使人们调查慢性金属污染对拉古纳河口系统(LES)本地牡蛎的长期生物影响。在这里,我们介绍了贻贝和海湾扇贝鳃和消化腺中生物标志物反应(过氧化氢酶、葡萄糖-6-磷酸脱氢酶、谷胱甘肽 S-转移酶和蛋白质羰基化)的种特异性和大小特异性变化。同时,还测量了软组织中八种金属(Al、Cd、Cr、Cu、Fe、Mn、Pb 和 Zn)的浓度。我们的分析表明,这两种物种中的金属水平均按以下顺序递减:Zn>Fe>Al>Cu>Mn>Cd。除 Cu 和 Al 外,两种贻贝物种的金属浓度没有差异。生物标志物结果突出表明,C. gasar 表现出更高的抗氧化反应,而 C. gigas 在暴露于 LES 污染物时表现出更高的生物转化能力,这种转化能力因组织而异。然而,C. gasar 表现出更高水平的蛋白质羰基化,但与金属无关。在我们的研究方法中,从生态毒理学的角度来看,观察金属的存在和与生物标志物相关的反应被认为是具有生物学相关性的,并为拉丁美洲河口未来的污染研究提供了基线。最后,我们建议在巴西南部的未来区域生物监测研究中,无论大小和体重如何,都采用贻贝和海湾扇贝的一系列生物标志物作为指示生物。