Abstract：
The effect of water acidification in combination with normoxia or hypoxia on the antioxidant capacity and oxidative stress markers in gills and hemolymph of the Mediterranean mussel (Mytilus galloprovincialis), as well as on gill microstructure, has been evaluated through an in vivo experiment. Mussels were exposed to a low pH (7.3) under normal dissolved oxygen (DO) conditions (8 mg/L), and hypoxia (2 mg/L) for 8 days, and samples were collected on days 1, 3, 6, and 8 to evaluate dynamic changes of physiological responses. Cytoplasmic concentrations of reactive oxygen species (ROS) and levels of DNA damage were measured in hemocytes, while the activity of catalase (CAT) and superoxide dismutase (SOD) and histopathological changes were assessed in gills. The results revealed that while water acidification did not significantly affect the activity of SOD and CAT in gills under normoxic and hypoxic conditions, there was a trend towards suppression of CAT activity at the end of the experimental period (day 8). Similarly, we did not observe increased formation of ROS in hemocytes or changes in the levels of DNA damage during the experimental period. These results strongly suggest that the oxidative stress response system in mussels is relatively stable to experimental conditions of acidification and hypoxia. Experimental acidification under normoxia and hypoxia caused changes to the structure of the gills, leading to various histopathological alterations, including dilation, hemocyte infiltration into the hemal sinuses, intercellular edema, vacuolization of epithelial cells in gill filaments, lipofuscin accumulation, changes in the shape and adjacent gill filaments, hyperplasia, exfoliation of the epithelial layer, necrosis, swelling, and destruction of chitinous layers (chitinous rods). Most of these alterations were reversible, non-specific changes that represent a general inflammatory response and changes in the morphology of the gill filaments. The dynamics of histopathological alterations suggests an active adaptive response of gills to environmental stresses. Taken together, our data indicate that Mediterranean mussels have a relative tolerance to water acidification and hypoxia at tissue and cellular levels.
摘要：
水酸化结合常氧或低氧对地中海贻贝（Mytilusgalloprovincialis）的g和血淋巴的抗氧化能力和氧化应激标志物的影响，以及在ill的微观结构上，已经通过体内实验进行了评估。贻贝在正常溶解氧（DO）条件（8mg/L）下暴露于低pH（7.3），和缺氧（2毫克/升）8天，并在第1、3、6和8天收集样品以评估生理反应的动态变化。在血细胞中测量活性氧（ROS）的细胞质浓度和DNA损伤水平，同时评估了g中过氧化氢酶（CAT）和超氧化物歧化酶（SOD）的活性以及组织病理学变化。结果表明，在常氧和低氧条件下，水酸化对g中SOD和CAT的活性没有显着影响。在实验期结束时(第8天)有抑制CAT活性的趋势。同样，在实验期间，我们没有观察到血细胞中ROS的形成增加或DNA损伤水平的变化。这些结果强烈表明，贻贝中的氧化应激反应系统对酸化和缺氧的实验条件相对稳定。常氧和缺氧下的实验性酸化会引起g的结构变化，导致各种组织病理学改变，包括扩张，血细胞浸润到血窦，细胞间水肿,g丝中上皮细胞的空泡化，脂褐素积累，形状和相邻的刺丝的变化，增生,上皮层的脱落，坏死,肿胀,和几丁质层（几丁质棒）的破坏。这些改变大部分是可逆的，代表一般炎症反应和g丝形态变化的非特异性变化。组织病理学改变的动力学表明g对环境压力的主动适应性反应。一起来看,我们的数据表明，地中海贻贝在组织和细胞水平上对水酸化和缺氧具有相对耐受性。
