Previous research has identified microplastics as new environmental pollutants that are widely distributed in a variety of environments, including aquaculture environments. However, the potential hazard of microplastics to aquaculture animals, especially toward lipid metabolism involved with the survival and growth of aquatic animal, has not yet been investigated. In the present study, redclaw crayfish (Cherax quadricarinatus) were exposed to different concentrations of 200 nm-sized polystyrene microspheres (0, 0.5, and 5 mg/L) for 21 days, to investigate the effects of microplastics on lipid metabolism. After ingestion, the microplastics were distributed in the intestines and hepatopancreas, and appeared to inhibit the growth of Cherax quadricarinatus. Subsequently, the lipid levels in the hepatopancreas and hemolymph was detected, and found that after 21 days of exposure, the lipid content and free fatty acids in the hepatopancreas and hemolymph decreased significantly, and total cholesterol and triglycerides levels increased significantly in the hemolymph. This might have been caused by insufficient intake of exogenous fat. A significant decrease in lipase activity also supported this view. The activity of lipoprotein lipase related to lipolysis in the hepatopancreas increased significantly, while the activity of fatty acid synthase related to fat synthesis increased, and the activity of acetyl-CoA carboxylase decreased. These results indicated disturbed lipid metabolism in the hepatopancreas. The significant increase of lipid transport-related low-density lipoprotein indicated that the lipolytic capacity was higher than the lipid synthesis capacity. The expression levels of fatty acid metabolism-related genes FAD6 and FABP decreased significantly, indicating that the fatty acid utilization ability of hepatopancreas cells was inhibited, which was consistent with the results of enzyme activities. Thus, microplastics represent a potential hazard to redclaw crayfish, at least on lipid metabolism. This study provided basic data on the ecotoxicological effects of microplastics on crustaceans.

中文翻译：

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暴露于水性聚苯乙烯微球对少年红爪小龙虾Cherax quadricarinatus肝胰腺脂质代谢的影响。

先前的研究已将微塑料识别为新型环境污染物，这些污染物广泛分布在包括水产养殖环境在内的各种环境中。然而，尚未研究微塑料对水产养殖动物的潜在危害，特别是对涉及水生动物生存和生长的脂质代谢的潜在危害。在本研究中，将红爪小龙虾（Cherax quadricarinatus）暴露于不同浓度的200 nm大小的聚苯乙烯微球（0、0.5和5 mg / L）中21天，以研究微塑料对脂质代谢的影响。摄入后，微塑料散布在肠和肝胰腺中，并似乎抑制了Cherax quadricarinatus的生长。随后，检测了肝胰腺和血淋巴中的脂质水平，并且发现暴露21天后，肝胰腺和血淋巴中的脂质含量和游离脂肪酸显着下降，而血淋巴中的总胆固醇和甘油三酸酯水平显着上升。这可能是由于外源脂肪摄入不足引起的。脂肪酶活性的显着下降也支持这一观点。肝胰脏中与脂解相关的脂蛋白脂肪酶活性显着增加，而与脂肪合成相关的脂肪酸合酶活性增加，乙酰辅酶A羧化酶活性下降。这些结果表明肝胰腺中脂质代谢紊乱。脂质转运相关的低密度脂蛋白的显着增加表明脂解能力高于脂质合成能力。脂肪酸代谢相关基因FAD6和FABP的表达水平显着降低，表明肝胰腺细胞对脂肪酸的利用能力受到抑制，与酶活性的结果一致。因此，至少在脂质代谢方面，微塑料代表了对红爪小龙虾的潜在危害。这项研究提供了有关微塑料对甲壳类动物生态毒理作用的基础数据。