College of Fisheries (Central Agricultural University), Lembucherra, Tripura 799210, India.
ICAR Research Complex for NEH Region, Tripura Center, Lembucherra, Tripura 799210, India.
Ecotoxicol Environ Saf. 2019 Apr 15;170:87-97. doi: 10.1016/j.ecoenv.2018.11.129. Epub 2018 Dec 4.
Iron is an essential element for many physiological functions of several organisms but in excess it causes toxicity. High iron content in water bodies of mountainous states is considered as one of the major factor, responsible for low productivity in aquaculture systems. But, till date comprehensive reports on the adverse effect of iron overload in aquatic organisms, especially cultured fishes are scanty. Therefore, the present study was undertaken to investigate the adverse effects of iron overload in economically important aquaculture fish species Labeo rohita. Three sub-lethal test concentration of iron (ferrous) viz., 1/16th, 1/8th and 1/4th of LC (post 96 h) i.e. 8.25, 16.51 and 33.01 mg L, respectively, were used for in vivo exposure. Blood cells and tissue samples of the control & exposed specimens were sampled at intervals of 24, 48, 72 and 96 h to assess alterations in hematological, oxidative stress and histological parameters. Significant changes in erythrocyte and leukocyte counts, hemoglobin, lipid peroxidation, antioxidant enzyme activity (super oxide dismutase and catalase) and tissue iron accumulation were observed in the exposed fish. Significant increase in lipid peroxidation, coupled with significant reduction in free radicals scavengers like super oxide dismutase and catalase revealed a compromised anti-oxidative defense mechanism in the fishes exposed to iron overload. Histological examination of gills and liver showed severe tissue injury and histological alternations. Severity was found to increase in time and concentration dependent manner. Perl's staining revealed accumulation of excess iron in liver of the exposed fish. The observed patho-physiological changes in the present study provide the most comprehensive insight of iron overload stress in L. rohita.
铁是许多生物体许多生理功能所必需的元素，但过量的铁会导致毒性。山区水体中铁含量高被认为是水产养殖系统生产力低下的主要因素之一。但是，迄今为止，关于铁过载对水生生物，特别是养殖鱼类的不良影响的综合报告很少。因此，本研究旨在研究铁过载对经济上重要的水产养殖鱼类罗非鱼的不良影响。本研究使用了三种亚致死铁（亚铁）测试浓度，即 LC（96 小时后）的 1/16、1/8 和 1/4，即 8.25、16.51 和 33.01mg/L，分别进行体内暴露。在暴露期间的 24、48、72 和 96 小时，从对照和暴露标本中采集血液细胞和组织样本，以评估血液学、氧化应激和组织学参数的变化。暴露鱼的红细胞和白细胞计数、血红蛋白、脂质过氧化、抗氧化酶活性（超氧化物歧化酶和过氧化氢酶）和组织铁积累都发生了显著变化。暴露于铁过载的鱼类中，脂质过氧化显著增加，而自由基清除剂如超氧化物歧化酶和过氧化氢酶的活性显著降低，表明抗氧化防御机制受损。鳃和肝脏的组织学检查显示出严重的组织损伤和组织变化。严重程度随时间和浓度的增加而增加。 Perl 染色显示暴露鱼肝脏中积累了过量的铁。本研究中观察到的病理生理变化为罗非鱼铁过载应激提供了最全面的见解。
