Thermal stress accelerates mercury chloride toxicity in Oreochromis niloticus via up-regulation of mercury bioaccumulation and HSP70 mRNA expression
| Autor: | Nabila M. Abdelaleem, Amel M. El Asely, Farag Malhat, Hatem Bakery, Asmaa F. Khafaga, Ahmed Abdeen, Rania M. Waheed, Mohamed Abuo-Salem, Ragab El-Shawarby |
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| Rok vydání: | 2019 |
| Předmět: |
Environmental Engineering
Antioxidant 010504 meteorology & atmospheric sciences medicine.medical_treatment 010501 environmental sciences 01 natural sciences Superoxide dismutase Nile tilapia medicine Environmental Chemistry Animals Food science RNA Messenger Waste Management and Disposal Ecosystem 0105 earth and related environmental sciences chemistry.chemical_classification biology Glutathione peroxidase Cichlids Mercury biology.organism_classification Pollution Bioaccumulation Up-Regulation Oreochromis Oxidative Stress chemistry Liver Catalase Toxicity Mercuric Chloride biology.protein |
| Zdroj: | The Science of the total environment. 718 |
| ISSN: | 1879-1026 |
| Popis: | Mercury (Hg) is an environmental pollutant that threatens aquatic life. Many environmental factors, including water temperature, are reported to influence the toxicity of dissolved chemicals in the aquatic ecosystem. Therefore, we investigated the impact of thermal stress on Hg-induced subchronic toxicity in Nile tilapia (Oreochromis niloticus). Fish were randomly allocated into five groups. Group I served as the control and kept at 25 °C. Groups II, III, IV, and V were reared at 25, 28, 31, and 34 °C, respectively, and co-exposed to HgCl2 (1/10 LC50) for 42 days. Blood and tissue samples were collected after 21 and 42 days. All HgCl2-exposed groups exhibited significant elevations in serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea, and creatinine, along with decreases in the serum total protein and albumin. In addition, marked reductions in antioxidant enzymes, including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSPx), were observed. Remarkable increases in Hg tissue concentrations were detected along with increases in heat shock protein (HSP) 70 mRNA expression. Interestingly, the patterns data that were recorded were more coincident with the water temperature than the period of exposure. In conclusion, water temperature and exposure period are two crucial factors modulating HgCl2-induced toxicity and bioaccumulation in Nile tilapia. Our findings provide new insights concerning the impact of thermal stress as an environmental factor on Hg toxicity and bioaccumulation in Nile tilapia and, in turn, on fish and fish consumer health. |
| Databáze: | OpenAIRE |
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