Universidade Federal de São João Del Rei, Campus Centro Oeste, Rua Sebastião Gonçalves Coelho, 400, 35501-296 Divinópolis, Minas Gerais, Brazil.
Universidade do Estado de Minas Gerais, Unidade Divinópolis, Av. Paraná, 3001, 35501-170 Divinópolis, Minas Gerais, Brazil; Universidade Federal de Minas Gerais Instituto de Ciências Biológicas ICB, Av. Antônio Carlos, 6627, 31270-901 Belo Horizonte, Minas Gerais, Brazil.
Sci Total Environ. 2020 Sep 15;735:139505. doi: 10.1016/j.scitotenv.2020.139505. Epub 2020 May 18.
The effects of the rupture of a mining tailings dam were investigated using the gills and liver of Astyanax lacustris as a proxy for environmental quality. The fish were exposed for seven days to water sampled forming four groups: upstream of the dam rupture (P1), and 22 km (P2); 48 km (P3); and 70 km (P4) downstream from the dam rupture in the Doce River basin. The control group received dechlorinated tap water. The dissolved concentrations of metals were determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). We evaluated the histology of the gills and liver, as well as, immunohistochemistry for HSP70 and Na/K ATPase (NKA) in the gills, and for P-gp in liver. In all sites we observed a mix of metals, with higher concentrations of Mn, Cd, As, and Cu/Cr in P1, P2, P3, and P4, respectively. All treatments groups showed histological changes in gills and liver, with the highest amount of these alterations found in the P2 group. Disorganization of the secondary lamellae, epithelial lifting, and mitochondria-rich cells (MRC) were observed in the gills. The parenchyma of the liver was rather disorganized, and hepatocytes and nuclei showed hypertrophy, vacuolization and cytoplasmic degeneration. A higher immunoreaction of HSP70 in P2 when compared with the other groups and lower labeling of HSP70 in the P4 was registered. In P2 and P3, NKA-positive cells were observed with hypertrophy and disorganization. Morphometric analyses of the liver revealed that all treatment groups presented a lower immunolabeling of P-gp when compared with the control group. Thus, the experimental approach revealed that the water from Doce basin can promote histological alterations in fish's liver and gills, as well as modulation of disruption of ionic balance, cellular responses to stress, and cell detoxification pathways.
采用亚达伯拉尖吻鲈（Astyanax lacustris）的鳃和肝脏作为环境质量的替代指标，研究了采矿尾矿坝破裂的影响。将鱼暴露于从大坝破裂处上游（P1）、22 公里（P2）、48 公里（P3）和 70 公里（P4）的 4 个水样组中，持续 7 天。对照组接受去氯自来水。采用电感耦合等离子体质谱法（ICP-MS）测定金属的溶解浓度。我们评估了鳃和肝脏的组织学，以及鳃中 HSP70 和 Na/K ATPase（NKA）的免疫组织化学，以及肝脏中 P-gp 的免疫组织化学。在所有地点，我们都观察到了混合金属，其中 Mn、Cd、As 和 Cu/Cr 的浓度在 P1、P2、P3 和 P4 中分别较高。所有处理组的鳃和肝脏都显示出组织学变化，其中 P2 组的变化最大。在鳃中观察到二级瓣的紊乱、上皮抬起和富线粒体细胞（MRC）。肝脏的实质组织相当紊乱，肝细胞和细胞核表现出肥大、空泡化和细胞质变性。与其他组相比，P2 组的 HSP70 免疫反应较高，而 P4 组的 HSP70 标记较低。在 P2 和 P3 中，观察到 NKA 阳性细胞肥大和紊乱。肝脏的形态计量学分析显示，与对照组相比，所有处理组的 P-gp 免疫标记均较低。因此，实验方法表明，Doce 流域的水会导致鱼类肝脏和鳃的组织学改变，以及离子平衡的破坏、细胞对应激的反应和细胞解毒途径的调节。
