East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, China.
East China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, China; Key Laboratory of East China Sea Fishery Resources Exploitation, Ministry of Agriculture, Shanghai, 200090, China.
Chemosphere. 2020 Mar;243:125241. doi: 10.1016/j.chemosphere.2019.125241. Epub 2019 Nov 11.
In lakes and reservoirs, harmful algal blooms and high pH have been deemed to be two important stressors related to eutrophication, especially in the case of CO depletion caused by dense blooms. However, the effects of these stressors on the economically important shellfish that inhabit these waters are still not well-understood. This study evaluated the combined effects of the harmful algae Microcystis aeruginosa (0%, 50%, and 100% of total dietary dry weight) and high pH (8.0, 8.5 and 9.0) on the antioxidant responses of the triangle sail mussel H. cumingii. The mussels were exposed to algae and high pH for 14 d, followed by a 7-day depuration period. Reactive oxygen species (ROS) in the mussel hemolymph, antioxidant and detoxifying enzymes, such as glutathione-S-transferase (GST), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and malondialdehyde (MDA) in the digestive glands were analyzed during the experimental period. GST, SOD and GPx activity levels and the content of GSH increased following exposure to toxic M. aeruginosa, whereas CAT activity was inhibited. pH showed no significant effects on the immune defense mechanisms and detoxification processes. However, a high pH could cause increased ROS and MDA levels, resulting in oxidative injury. After a 7-day depuration period, exposure to toxic M. aeruginosa or high pH resulted in latent effects for most of the examined parameters. The treatment group exposed to the highest pH (9.0) displayed an increased oxidation state compared with the other pH treatments (8.0 and 8.5) for the same concentrations of toxic M. aeruginosa. The trends observed for ROS, MDA, GPx, GST, SOD and GSH levels indicated that a high density of toxic algae could result in severe and continuous effects on mussel health.
在湖泊和水库中，富营养化与有害藻类大量繁殖和高 pH 值被认为是两个重要的胁迫因素，尤其是在由于密集藻类大量繁殖而导致 CO 消耗的情况下。然而，这些胁迫因素对栖息在这些水域中的经济上重要的贝类的影响仍未被充分了解。本研究评估了有害藻类铜绿微囊藻（占总膳食干重的 0%、50%和 100%）和高 pH 值（8.0、8.5 和 9.0）对三角帆蚌 H. cumingi 的抗氧化反应的联合影响。贻贝暴露于藻类和高 pH 值下 14 天，随后进行 7 天的净化期。在实验期间分析了贻贝血淋巴中的活性氧（ROS）、抗氧化和解毒酶（如谷胱甘肽-S-转移酶（GST）、谷胱甘肽（GSH）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GPx）和丙二醛（MDA））的含量。暴露于有毒铜绿微囊藻后，GST、SOD 和 GPx 活性水平和 GSH 含量增加，而 CAT 活性受到抑制。pH 值对免疫防御机制和解毒过程没有显著影响。然而，高 pH 值可能导致 ROS 和 MDA 水平增加，从而导致氧化损伤。在 7 天的净化期后，暴露于有毒铜绿微囊藻或高 pH 值会导致大多数检测参数出现潜伏效应。与其他 pH 值处理（8.0 和 8.5）相比，暴露于最高 pH 值（9.0）的处理组在相同浓度的有毒铜绿微囊藻下显示出更高的氧化状态。ROS、MDA、GPx、GST、SOD 和 GSH 水平的变化趋势表明，高密度的有毒藻类可能对贻贝健康造成严重且持续的影响。
