Department of Physiological Sciences, State University of Londrina (UEL), Londrina, Paraná, Brazil.
Department of Physiological Sciences, State University of Londrina (UEL), Londrina, Paraná, Brazil.
Aquat Toxicol. 2021 Aug;237:105874. doi: 10.1016/j.aquatox.2021.105874. Epub 2021 May 25.
Copper is an essential metal for life. However, in excess, it can lead to osmoregulatory disorders and oxidative stress in fish and these effects appear to be species specific. In order to evaluate the effects of copper and to compare the sensitivity of two Neotropical fishes that co-occur in nature as prey (Astyaynax altiparanae) and predator (Hoplias malabaricus), the fish were exposed to three concentrations of Cu (5 μg L, 10 μg L, and 20 μg L) for 96 h. At the end of the experimental period, copper concentration in tissues, osmoregulatory parameters, oxidative stress biomarkers, plasma glucose, muscle glycogen and acetylcholinesterase activity were evaluated. Fish mortality (25%) was only observed for A. altiparanae exposed to Cu 20 μg L. The results revealed species-specific ionic disturbances. Despite hypocalcemia, H. malabaricus showed an increase in the main gill ATPases, which probably guaranteed the maintenance of plasma Na. In A. altiparanae, there was no change in ATPase activity in the gills and hyponatremia was observed at all copper concentrations, as well as a decrease in plasma Cl in the Cu 20 μg L group. The strategy adopted by H. malabaricus seems to have contributed to the absence of copper accumulation in the tissues, in addition to possibly being related to the absence of oxidative stress in this species. On the other hand, there was an increase in the concentration of copper in the gills, liver, and gastrointestinal tract of A. altiparanae, as well as oxidative stress evidenced by increased lipoperoxidation in the liver and damage to erythrocytes DNA. This work reinforces the idea that copper effects are species specific and that a given concentration may not be safe for different species which can coexist in the same environment.
铜是生命必需的金属。然而，过量的铜会导致鱼类渗透压调节障碍和氧化应激，而这些影响似乎具有物种特异性。为了评估铜的影响，并比较两种在自然界中同时作为猎物（Astyaynax altiparanae）和捕食者（Hoplias malabaricus）共存的新热带鱼类的敏感性，将这些鱼暴露在三种铜浓度（5μg/L、10μg/L 和 20μg/L）下 96 小时。在实验结束时，评估了组织中的铜浓度、渗透压调节参数、氧化应激生物标志物、血浆葡萄糖、肌肉糖原和乙酰胆碱酯酶活性。只有暴露在 Cu 20μg/L 下的 A. altiparanae 才观察到鱼类死亡率（25%）。结果显示出物种特异性的离子紊乱。尽管低血钙，H. malabaricus 表现出主要鳃 ATP 酶的增加，这可能保证了血浆 Na 的维持。在 A. altiparanae 中，鳃中的 ATP 酶活性没有变化，在所有铜浓度下都观察到低钠血症，并且在 Cu 20μg/L 组中血浆 Cl 减少。H. malabaricus 采用的策略似乎有助于防止组织中铜的积累，此外，这可能与该物种中不存在氧化应激有关。另一方面，A. altiparanae 的鳃、肝脏和胃肠道中的铜浓度增加，并且肝脏的脂质过氧化和红细胞 DNA 损伤表明存在氧化应激。这项工作强化了这样一种观点，即铜的影响具有物种特异性，并且给定的浓度对于可能在同一环境中共存的不同物种可能并不安全。
