Macirella Rachele, Brunelli Elvira
Department of Biology, Ecology and Earth Science, University of Calabria, Via P. Bucci 4/B, 87036 Rende (Cosenza), Italy.
Int J Mol Sci. 2017 Apr 13;18(4):824. doi: 10.3390/ijms18040824.
Mercury (Hg) is a global pollutant that may exert its toxic effects on living organisms and is found in both aquatic and terrestrial ecosystems in three chemical forms; elemental, organic, and inorganic. The inorganic form (iHg) tends to predominantly accumulate in aquatic environments. The gill apparatus is a very dynamic organ that plays a fundamental role in gas exchange, osmoregulation, acid-base regulation, detoxification, and excretion, and the gills are the primary route of waterborne iHg entrance in fish. In the present work we investigated the morphofunctional and ultrastructural effects in gills after 96 h exposure to two low HgCl₂ concentrations (7.7 and 38.5 µg/L). Our results clearly demonstrated that a short-term exposure to low concentrations of mercury chloride resulted in gill morphology alterations and in the modifications of both NaK⁺-ATPase and metallothioneins (MTs) expression pattern. The main morphological effects recorded in this work were represented by hyperplasia and ectopia of chloride cells (CCs), lamellar fusion, increased mucous secretion, alteration of pavement cells (PVCs), detachment of the secondary epithelium, pillar cell degeneration, degeneration, and apoptosis. Trough immunohistochemistry and real-time PCR analysis also showed a dose-related modulation of Na⁺/K⁺-ATPase and MTs.
汞（Hg）是一种全球污染物，可能对生物体产生毒性作用，在水生和陆地生态系统中以三种化学形式存在，即元素汞、有机汞和无机汞。无机汞形式（iHg）往往主要在水生环境中积累。鳃器官是一个非常活跃的器官，在气体交换、渗透调节、酸碱调节、解毒和排泄中起着重要作用，鳃是鱼类水体中无机汞进入的主要途径。在本研究中，我们调查了在暴露于两种低浓度HgCl₂（7.7和38.5 µg/L）96小时后鳃的形态功能和超微结构影响。我们的结果清楚地表明，短期暴露于低浓度氯化汞会导致鳃形态改变以及钠钾⁺-ATP酶和金属硫蛋白（MTs）表达模式的改变。本研究中记录的主要形态学影响表现为氯细胞（CCs）的增生和异位、板层融合、黏液分泌增加、扁平细胞（PVCs）改变、次级上皮脱落、柱状细胞变性、退化和凋亡。通过免疫组织化学和实时PCR分析还显示了钠⁺/钾⁺-ATP酶和金属硫蛋白的剂量相关调节。
