Abstract

Phosmet is a non-systemic organophosphorus insecticide exerting its toxicity by inhibiting acetylcholinesterase upon entering the body via contact, ingestion and inhalation. Data regarding its sublethal effects on fish are limited, and therefore, with this study it was aimed to investigate the effects of phosmet on liver and brain tissues of juvenile Oncorhynchus mykiss following 24, 48, 72 and 96 h of exposure to 5, 25 and 50 μg/l concentrations. Pesticide treatment caused notable decrease in the levels of serum glucose, protein and cholesterol, whereas there was prominent elevation in the activities of alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase. Anticholinesterase activity of phosmet was observed in brain tissue reaching maximum of 46%. In both tissues, increase in the activities of superoxide dismutase, catalase and glutathione peroxidase and level of glutathione was accompanied by elevated thiobarbituric acid reactive substances level. Our results clearly indicate the modulatory effect of phosmet on acetylcholinesterase activity and its potency to provoke oxidative stress condition. The determined alteration in alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase activities indicates hepatotoxic potential of pesticide; meanwhile, obtained hypoglycaemia and hypoproteinaemia are evaluated as adaptive responses to handle the stress to survive.

中文翻译：

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亚硫磷对虹鳟鱼 (Oncorhynchus mykiss) 的毒性和生化反应

摘要

Phosmet 是一种非内吸性有机磷杀虫剂，通过接触、摄入和吸入进入体内后抑制乙酰胆碱酯酶发挥其毒性。关于其对鱼类的亚致死影响的数据有限，因此，本研究旨在调查亚硫磷对幼年Oncorhynchus mykiss肝脏和脑组织的影响在 5、25 和 50 μg/l 浓度下暴露 24、48、72 和 96 小时后。农药处理导致血清葡萄糖、蛋白质和胆固醇水平显着降低，而丙氨酸氨基转移酶、天冬氨酸氨基转移酶和碱性磷酸酶的活性显着升高。在脑组织中观察到亚硫磷的抗胆碱酯酶活性最高可达 46%。在这两种组织中，超氧化物歧化酶、过氧化氢酶和谷胱甘肽过氧化物酶的活性和谷胱甘肽水平的增加伴随着硫代巴比妥酸反应物质水平的升高。我们的结果清楚地表明亚硫磷对乙酰胆碱酯酶活性的调节作用及其引发氧化应激条件的效力。确定的丙氨酸氨基转移酶改变，天冬氨酸氨基转移酶和碱性磷酸酶活性表明农药的肝毒性潜力；同时，获得的低血糖和低蛋白血症被评估为应对生存压力的适应性反应。