Aquaculture Department, Faculty of Natural Resources and the Environment, Behbahan Khatam Alanbia University of Technology, Behbahan, Iran.
Department of Clinical Sciences, School of Veterinary Medicine, Shiraz University, Shiraz, Iran.
Chemosphere. 2019 Dec;236:124335. doi: 10.1016/j.chemosphere.2019.07.066. Epub 2019 Jul 10.
The growing accumulation of microplastics (MPs) in aquatic environments is a global concern. MPs are capable to interact with other environmental contaminants, including heavy metals, altering their toxicity. The aim of the study was to investigate the sub-lethal effects of cadmium chloride (Cd) alone and in combination with MPs on common carp (Cyprinus carpio). Multi-biomarkers, including plasma biochemical parameters and intrinsic immunological factors, were measured after 30 days of exposure. Exposure to Cd or NPs reduced the plasma activities of acetylcholinesterase (AChE) and gamma-glutamyl-transferase (GGT) and increased aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH) and alkaline phosphatase (ALP). Exposure to both compounds enhanced the observed effects except for AST activity and ALP at the highest concentrations, whereas evidenced an antagonistic interaction in ALT. Plasma total protein, albumin, and globulin levels were decreased, and the levels of glucose, triglyceride, and cholesterol levels increased mainly in the Cd groups with no additional effects derived from the co-exposure to both stressors. Lysozyme and alternative complement (ACH50) activities and the levels of total immunoglobulins, and complement C3 and C4 in fish exposed to Cd and MPs were lower than those in the control group and this decrease was more significant by the mixture of both compounds. These findings showed that the exposure to Cd or MPs alone is toxic to fish altering the biochemical and immunological parameters. Moreover, these alterations are even greater when the Cd and the MPS are combined suggesting synergistic effects in increasing Cd toxicity and vice versa.
水生环境中微塑料（MPs）的不断积累是一个全球性的关注点。MPs 能够与其他环境污染物（包括重金属）相互作用，改变其毒性。本研究的目的是研究氯化镉（Cd）单独和与 MPs 结合对鲤鱼（Cyprinus carpio）的亚致死效应。在暴露 30 天后，测量了包括血浆生化参数和固有免疫因子在内的多种生物标志物。暴露于 Cd 或 NPs 会降低血浆乙酰胆碱酯酶（AChE）和γ-谷氨酰转移酶（GGT）的活性，并增加天冬氨酸转氨酶（AST）、丙氨酸转氨酶（ALT）、乳酸脱氢酶（LDH）和碱性磷酸酶（ALP）的活性。暴露于两种化合物会增强观察到的效应，但在最高浓度下除外 AST 活性和 ALP，而在 ALT 中则表现出拮抗相互作用。血浆总蛋白、白蛋白和球蛋白水平降低，葡萄糖、甘油三酯和胆固醇水平升高，主要发生在 Cd 组，而没有来自两种应激源共同暴露的额外影响。暴露于 Cd 和 MPs 的鱼类的溶菌酶和替代补体（ACH50）活性以及总免疫球蛋白和补体 C3 和 C4 的水平低于对照组，并且这种下降在两种化合物混合时更为显著。这些发现表明，单独暴露于 Cd 或 MPs 会对鱼类造成毒性，改变生化和免疫参数。此外，当 Cd 和 MPS 结合时，这些变化甚至更大，表明 Cd 毒性的协同作用和反之亦然。
