Laboratório de Biomarcadores de Contaminação Aquática e Imunoquímica, Departamento de Bioquímica, Universidade Federal de Santa Catarina, Florianópolis, Brazil.
Aquat Toxicol. 2011 Oct;105(3-4):652-60. doi: 10.1016/j.aquatox.2011.09.003. Epub 2011 Sep 14.
Understanding the toxic mechanisms by which organisms cope to environmental stressful conditions is a fundamental question for ecotoxicology. In this study, we evaluated biochemical responses and hydrocarbons bioaccumulation of the mangrove oyster Crassostrea brasiliana exposed for 96 h to four sublethal concentrations of diesel fuel water-accommodated fraction (WAF). For that purpose, enzymatic activities (SOD, CAT, GPx, GR, G6PDH, GST and GGT), HSP60 and HSP90 immunocontent and lipid peroxidation (LPO) levels were determined in the gill and digestive gland of oysters and related to the hydrocarbons accumulated in the whole soft tissues. The results of this study revealed clear biochemical responses to diesel fuel WAF exposure in both tissues of the oyster. The capacity of C. brasiliana to bioaccumulate aliphatic and aromatic hydrocarbons in a dose-dependent manner is a strong indication of its suitability as a model in biomonitoring programs along the Brazilian coast, which was also validated by the response of the antioxidant defenses, phase II biotransformation and chaperones. HSP60 levels and GGT activity were the most promising biomarkers in the gill, while GST and GR activities stood out as suitable biomarkers for the detection of diesel toxicity in the digestive gland. The decrease of SOD activity and HSP90 levels may also reflect a negative effect of diesel exposure regardless the tissue. The present results provide a sound preliminary report on the biochemical responses of C. brasiliana challenged with a petroleum by-product and should be carefully considered for use in the monitoring of oil and gas activities in Brazil.
了解生物应对环境胁迫条件的毒性机制是生态毒理学的一个基本问题。在这项研究中，我们评估了暴露在四种亚致死柴油燃料水容纳分数（WAF）浓度下 96 小时的红树林牡蛎 Crassostrea brasiliana 的生化反应和碳氢化合物生物累积。为此，测定了牡蛎鳃和消化腺中的酶活性（SOD、CAT、GPx、GR、G6PDH、GST 和 GGT）、HSP60 和 HSP90 免疫含量以及脂质过氧化（LPO）水平，并将其与整个软组织中累积的碳氢化合物相关联。这项研究的结果表明，柴油燃料 WAF 暴露在牡蛎的两种组织中都引起了明显的生化反应。C. brasiliana 能够以剂量依赖的方式生物累积脂肪族和芳香族碳氢化合物，这强烈表明它适合作为巴西沿海生物监测计划中的模型，这也得到了抗氧化防御、二期生物转化和伴侣蛋白反应的验证。HSP60 水平和 GGT 活性是鳃中最有前途的生物标志物，而 GST 和 GR 活性则是检测消化腺中柴油毒性的合适生物标志物。SOD 活性和 HSP90 水平的降低也可能反映出无论组织如何，柴油暴露的负面影响。本研究结果为 C. brasiliana 受到石油副产品挑战时的生化反应提供了可靠的初步报告，应在巴西石油和天然气活动监测中谨慎考虑。
