Ruđer Bošković Institute, Division of Materials Chemistry, Laboratory for Biotechnology in Aquaculture, 10000 Zagreb, Croatia.
Ruđer Bošković Institute, Division for Marine and Environmental Research, Laboratory for Biological Effects of Metals, 10000 Zagreb, Croatia.
Sci Total Environ. 2018 Nov 15;642:656-664. doi: 10.1016/j.scitotenv.2018.06.045. Epub 2018 Jun 14.
In the present study novel histopathological approach, using fish intestine as a sensitive bioindicator organ of pollution impact in the freshwater ecosystem, was proposed. Histopathological alterations were compared between native brown trout (Salmo trutta Linnaeus, 1758) from the reference (Krka River spring) and pollution impacted location (influence of technological/municipal wastewaters and agricultural runoff near the Town of Knin) of the karst Krka River in Croatia. In brown trout from both locations, severe parasitic infestation with acanthocephalan species Dentitruncus trutae was found, enabling evaluation of acanthocephalan infestation histopathology, which indicated parasite tissue reaction in a form of inflammatory, necrotic and hyperplastic response that extended throughout lamina epithelialis mucosae, lamina propria, and lamina muscularis mucosae. New semi-quantitative histological approach was proposed in order to foresee alterations classified in three reaction patterns: control tissue appearance, moderate (progressive) tissue impairment and severe (regressive and inflammatory) tissue damage. The most frequent progressive alteration was hyperplasia of epithelium on the reference site, whereas the most frequent regressive alterations were atrophy and necrosis seen on the polluted site. Furthermore, histopathological approach was combined with micromorphological and macromorphological assessment as an additional indicator of pollution impact. Among 15 observed intestinal measures, two biomarkers of intestinal tissue damage were indicated as significant, height of supranuclear space (hSN) and number of mucous cells over 100 μm fold distance of intestinal mucosa (nM), which measures were significantly lower in fish from polluted area compared to the reference site. Obtained results indicated that combined histological and morphological approach on fish intestinal tissue might be used as a valuable biological tool for assessing pollution impact on aquatic organisms. Therefore, semi quantitative scoring and multiparametric morphological assessment of intestinal tissue lesion magnitude should become a common approach to handle environmental pollution impact.
在本研究中，提出了一种新的组织病理学方法，将鱼类肠道作为淡水生态系统中污染影响的敏感生物标志物器官。比较了来自克罗地亚喀斯特河 Krka 河的参考（Krka 河源头）和受污染（受技术/市政废水和城镇附近农业径流影响）地点的本地棕色鳟鱼（Salmo trutta Linnaeus，1758）的组织病理学变化。在两个地点的鳟鱼中，都发现了严重的寄生棘头虫属 Dentitruncus trutae 感染，这使得棘头虫感染的组织病理学得以评估，表明寄生虫组织反应呈炎症、坏死和增生反应的形式，延伸至黏膜上皮、固有层和黏膜肌层。提出了一种新的半定量组织学方法，以便预测分为三种反应模式的变化：正常组织外观、中度（进行性）组织损伤和严重（退行性和炎症性）组织损伤。在参考地点，最常见的进行性变化是上皮增生，而在污染地点，最常见的退行性变化是萎缩和坏死。此外，组织病理学方法与微观形态学和宏观形态学评估相结合，作为污染影响的附加指标。在所观察到的 15 个肠道指标中，有两个肠道组织损伤的生物标志物被认为是显著的，即核上空间高度（hSN）和黏膜 100 μm 折叠距离上的粘蛋白细胞数（nM），与参考地点相比，污染地区鱼类的这些指标显著较低。研究结果表明，鱼类肠道组织的综合组织学和形态学方法可作为评估水生生物污染影响的有价值的生物学工具。因此，半定量评分和肠道组织病变程度的多参数形态学评估应该成为处理环境污染影响的常见方法。
