不同粒径微塑料对中华绒螯蟹幼蟹组织结构及肝胰腺抗氧化能力的影响

Toxic effects of different particle size polystyrene microbeads on juvenile Eriocheir sinensis

以中华绒螯蟹为实验对象,研究了3种不同粒径(5μm、1μm、100 nm)的聚苯乙烯(Polystyrene)微塑料颗粒对中华绒螯蟹幼蟹的毒性效应。将中华绒螯蟹幼蟹分别暴露于3种粒径的聚苯乙烯微塑料1 d、3 d、7 d后,对其肝胰腺损伤指标:谷丙转氨酶(ALT)、谷草转氨酶(AST);血清免疫指标:碱性磷酸酶(AKP)、酸性磷酸酶(ACP);氧化应激指标:丙二醛(MDA)、过氧化氢酶(CAT);神经毒性指标:乙酰胆碱酯酶(AchE)进行分析。此外通过苏木精-伊红(H.E)染色法观察鳃、肝胰腺组织病变情况。研究结果表明,暴露于微塑料7 d后,100 nm组的MDA含量显著增高,CAT活性显著降低,3个处理组的AKP活性均显著降低,1μm、100 nm组的ACP活性显著降低。AST、ALT和AchE活性均随着粒径减小和暴露时间的延长活性逐渐降低。不同粒径的聚苯乙烯都能对中华绒螯蟹造成不同程度的肝胰腺损伤、使其氧化应激和免疫能力下降,其毒性排序依次是100 nm>1μm>5μm,说明粒径大小是影响中华绒螯蟹健康和造成组织损伤的重要因素之一。本研究结果为深入理解微塑料对淡水甲壳动物的毒性效应提供了基础数据和理论依据。

Studies on the biological effects of microplastics pollution on aquatic animals mostly focused on the ocean,but the potential effects on freshwater organisms are less known.In this study,the effects of polystyrene(PS)particles with different particle sizes(5μm,1μm,100 nm)on juvenile Chinese mitten crab(Eriocheir sinensis)were investigated.Hepatopancreas injury index:alanine aminotransferase(ALT),aspartate aminotransferase(AST);serum immune index:alkaline phosphatase(AKP),acid phosphatase(ACP);Oxidative stress index:malondialdehyde(MDA),catalase(CAT);and neurotoxicity index:acetylcholinesterase(AchE)were analyzed.The pathological changes of gills and hepatopancreas were analyzed by hematoxylin-eosin(H.E)staining.The results showed that exposure to microplastics after 7 d,100 nm group had significantly higher MDA content,CAT activity decreased significantly,the AKP activity of three treatment group were significantly lower,and 1μm and 100 nm group of ACP activity was significantly reduced.The activities of AST,ALT and AchE gradually decreased with the decrease of particle size and the extension of exposure time.In conclusion,microplastics with different particle sizes caused varying degrees of hepatopancreas injury,oxidative stress and reduced immune capacity in crabs.The toxicity level was ranked as follows:100 nm>1μm>5μm,indicating that the particle size was one of the most important factors affecting the health of Chinese mitten crabs.This study provides basic data and theoretical basis for further understanding the toxic effects of microplastics on freshwater crustaceans.