Department of Biological Science, Covenant University, P.M.B. 1023, Ota, Ogun State, Nigeria.
Department of Animal and Environmental Biology, University of Benin, P.M.B. 1154, Benin City, Nigeria.
Sci Rep. 2020 Mar 20;10(1):5180. doi: 10.1038/s41598-020-62024-9.
The aim of the study was to comparatively analyze the interrelationships among iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), lead (Pb), cadmium (Cd), chromium (Cr) and total hydrocarbons (THCs) in the gills, intestines and muscles of Clarias gariepinus collected from Osse River, Nigeria, between the periods of April, 2013 to September, 2014. The trace metals in the fish tissues were analyzed using Atomic Absorption Spectrophotometer (AAS, Philips model PU 9100), while total hydrocarbons were analyzed using High Performance Liquid Chromatograph (HPLC,Prominence Dual brand from HGE) equipped with a detector Shimadzu UV-Visible (UV-Vis Prominence SPD 20 A). The concentrations of trace metals and THCs in the tissues were subjected to principal component analysis (PCA), in conjunction with hierarchical cluster analysis (HCA), backed up by correlation analysis (CA). In the most prioritized component among the hierarchies of contaminants, characterized as principal component 1, results of communality extractions and rotated component matrices revealed the order of contaminants was Mn > Cu > Zn > Fe > Cr in the intestines, Cr > Cu > THCs > Mn > Fe in the muscle, while Pb > Cr > Fe > Mn was the order in the gills of the fish. Iron inhibited accumulation of the other trace metals in the gills, where its threshold of essentiality was maximal. Noteworthy is the fact that Mn and Cu were the most active components in the muscle and concurrently of excess concentrations in the tissue, which is the major edible part of fish, and constitutes its main body weight, hence holds its nutritional and economic values. High level of variability which occurred in the toxicant profile across the tissues of C. gariepinus is a function of uptake route, varied organ functions and specificity of tissue permeability of the compared organs. The study demonstrated variability in organ accumulation capacity and toxicant's competitiveness irrespective of bioavailability. The study provides data useful for future ecotoxicological studies and safety of consumers of the fish.
本研究旨在比较分析 2013 年 4 月至 2014 年 9 月期间从尼日利亚奥塞河采集的蓝鲶（Clarias gariepinus）鳃、肠和肌肉中铁（Fe）、锰（Mn）、锌（Zn）、铜（Cu）、铅（Pb）、镉（Cd）、铬（Cr）和总碳氢化合物（THCs）之间的相互关系。使用原子吸收分光光度计（AAS，飞利浦型号 PU 9100）分析鱼组织中的痕量金属，使用高效液相色谱（HPLC，来自 HGE 的 Prominence Dual 品牌）配备 Shimadzu UV-可见（UV-Vis Prominence SPD 20A）检测器分析总碳氢化合物。组织中的痕量金属和 THCs 浓度进行主成分分析（PCA），结合层次聚类分析（HCA），并辅以相关分析（CA）。在污染物层次结构中优先考虑的成分中，作为主成分 1，特征是共因子提取和旋转成分矩阵的结果表明，在肠道中污染物的顺序为 Mn>Cu>Zn>Fe>Cr，在肌肉中为 Cr>Cu>THCs>Mn>Fe，而在鱼的鳃中为 Pb>Cr>Fe>Mn。铁抑制了鳃中其他痕量金属的积累，其必需性阈值最大。值得注意的是，Mn 和 Cu 是肌肉中最活跃的成分，同时也是组织中过量浓度的成分，肌肉是鱼的主要可食用部分，构成了其主要体重，因此具有其营养价值和经济价值。蓝鲶不同组织中毒性物质谱的高度变异性是由于吸收途径、不同器官功能和比较器官组织通透性的特异性所致。该研究表明，无论生物利用度如何，器官积累能力和毒物的竞争力都存在变异性。该研究为未来的生态毒理学研究和鱼类消费者的安全提供了有用的数据。
