Zoology Department, Faculty of Science, Assiut University, 71516 Assiut, Egypt.
Anatomy, Histology and Embryology Department, Faculty of Veterinary Medicine, Assiut University, Assiut, Egypt.
Aquat Toxicol. 2019 Feb;207:83-90. doi: 10.1016/j.aquatox.2018.12.002. Epub 2018 Dec 3.
Melanomacrophage centres (MMCs) play a key role in the immune response in fish. They are considered sensitive bio-monitoring structures with roles in the assessment of toxicant impacts. The aim of this study was to examine the potential histopathological effect of 4-nonylphenol (4-NP) on hepatic MMCs in Clarias gariepinus. To achieve this objective, adult male fish were divided randomly and equally into two groups: a control group and a group that was exposed to 4-NP (dissolved in water at a dose of 0.1 mg/L) for 21 days. The 4-NP-intoxicated hepatic MMCs contained numerous necrotic macrophages. Superoxide dismutase 2 was immuno-expressed in the hepatic MMCs in both groups, with no significant difference. Histomorphometric examination revealed that the sizes and numbers of MMCs were dramatically higher in the livers of 4-NP-exposed C. gariepinus than in control fish. Following 4-NP challenge, in the liver, the abundance of lipofuscin and haemosiderin pigments increased, and single-pigmented macrophages, aggregated groups of deformed red blood cells (RBCs) and macrophages were present near blood vessels and hepatic sinusoids. These results reveal that 4-NP exerts immunological effects on hepatic MMCs in C. gariepinus and support the utility of MMCs as a cytological biomarker for aquatic exposure to 4-NP.
黑素巨噬细胞中心（MMCs）在鱼类的免疫反应中起着关键作用。它们被认为是敏感的生物监测结构，在评估毒物影响方面具有作用。本研究旨在检查 4-壬基酚（4-NP）对奥利亚罗非鱼（Clarias gariepinus）肝 MMC 潜在的组织病理学影响。为了实现这一目标，成年雄性鱼被随机均等分为两组：对照组和暴露于 4-NP（溶于水中，剂量为 0.1mg/L）21 天的暴露组。4-NP 中毒的肝 MMC 含有大量坏死的巨噬细胞。两组肝 MMC 中均有超氧化物歧化酶 2 的免疫表达，无显著差异。组织形态学检查显示，暴露于 4-NP 的奥利亚罗非鱼肝中 MMC 的大小和数量明显高于对照组。在肝脏中，暴露于 4-NP 后，脂褐素和含铁血黄素的含量增加，单色素巨噬细胞、变形红细胞（RBC）聚集群和巨噬细胞出现在血管和肝窦附近。这些结果表明，4-NP 对奥利亚罗非鱼肝 MMC 产生免疫作用，并支持 MMC 作为水生暴露于 4-NP 的细胞学生物标志物的效用。
