Department of Biology, University of Padova, Via Ugo Bassi 58/B, 35121 Padova, Italy.
Department of Biology, University of Padova, Via Ugo Bassi 58/B, 35121 Padova, Italy.
Environ Pollut. 2018 Sep;240:925-937. doi: 10.1016/j.envpol.2018.05.005. Epub 2018 Jun 18.
CO-driven acidification and emerging contaminants, such as pharmaceuticals, pose new threats for the maintenance of natural populations of marine organisms by interfering with their normal biochemical pathways and defences. The combined effects of seawater acidification, as predicted in climate change scenarios, and an emerging contaminant (the non-steroidal anti-inflammatory drug, NSAID, diclofenac) on oxidative stress-related parameters were investigated in the Mediterranean mussel Mytilus galloprovincialis and the Manila clam Ruditapes philippinarum. A flow-through system was used to carry out a three-week exposure experiment with the bivalves. First, the animals were exposed to only three pH values for 7 days. The pH was manipulated by dissolving CO in the seawater to obtain two reduced pH treatments (pH -0.4 units and pH -0.7 units), which were compared with seawater at the natural pH level (8.1). Thereafter, the bivalves were concomitantly exposed to the three experimental pH values and environmentally relevant concentrations of diclofenac (0.00, 0.05 and 0.50 μg/L) for an additional 14 days. The activities of superoxide dismutase, catalase and cyclooxygenase, and lipid peroxidation and DNA strand-break formation were measured in both the gills and digestive gland after 7, 14 and 21 days of exposure to each experimental condition. The results show that the biochemical parameters measured in both the mussels and clams were more influenced by the reduced pH than by the contaminant or the pH*contaminant interaction, although the biomarker variation patterns differed depending on the species and tissues analysed. Generally, due to increases in its antioxidant defence, M. galloprovincialis was more resistant than R. philippinarum to both diclofenac exposure and reduced pH. Conversely, reduced pH induced a significant decrease in COX activity in both the gills and digestive gland of clams, possibly resulting in the increased DNA damage observed in the digestive gland tissue.
CO 驱动的酸化和新兴污染物（如药品）通过干扰海洋生物的正常生化途径和防御机制，对维持海洋生物自然种群构成新的威胁。在气候变化情景预测的海水酸化和新兴污染物（非甾体抗炎药，双氯芬酸）的联合作用下，对来自地中海贻贝 Mytilus galloprovincialis 和菲律宾蛤仔 Ruditapes philippinarum 的与氧化应激相关的参数进行了研究。采用流动系统对双壳类动物进行了为期三周的暴露实验。首先，仅将动物暴露于三种 pH 值下 7 天。通过将 CO2 溶解在海水中来调节 pH 值，以获得两种降低的 pH 值处理（pH 值降低 0.4 个单位和 pH 值降低 0.7 个单位），并将其与自然 pH 值（8.1）下的海水进行比较。此后，双壳类动物同时暴露于三种实验 pH 值和环境相关浓度的双氯芬酸（0.00、0.05 和 0.50 μg/L），持续 14 天。在暴露于每种实验条件 7、14 和 21 天后，测量了贻贝和蛤仔鳃和消化腺中的超氧化物歧化酶、过氧化氢酶和环氧化酶的活性以及脂质过氧化和 DNA 链断裂的形成。结果表明，与污染物或 pH*污染物相互作用相比，双壳类动物和蛤仔中测量的生化参数受降低的 pH 值影响更大，尽管生物标志物变化模式因物种和分析组织而异。一般来说，由于抗氧化防御能力的提高，与双氯芬酸暴露和降低的 pH 值相比，贻贝 M. galloprovincialis 的抵抗力更强。相反，降低的 pH 值导致双壳类动物的鳃和消化腺中的 COX 活性显著降低，这可能导致在消化腺组织中观察到的 DNA 损伤增加。
