微塑料对四角蛤蜊滤食、呼吸和免疫指标的影响

Effects of microplastics on filtration,respiratory,and immune indexes of Mactra veneriformis

为探讨微塑料对四角蛤蜊生理行为和免疫系统的影响,研究了不同浓度(1×10^(4)粒/L和1×10^(6)粒/L)和不同粒径(1μm和80 nm)的聚苯乙烯(PS)暴露对四角蛤蜊滤食率、呼吸率、丙二醛(MDA)浓度和过氧化氢酶(CAT)､超氧化物歧化酶(SOD)､酸性磷酸酶(ACP)、碱性磷酸酶(AKP)活性的影响。结果表明,仅1μm低浓度组对四角蛤蜊滤食率有显著影响;在高浓度、大粒径微塑料暴露下的四角蛤蜊呼吸率显著上升;SOD和CAT活性均在实验初期显著上升,实验后期呈下降趋势;ACP的活性在实验前期显著上升,在后期逐渐下降至与对照组无显著差异;AKP活性在3d后发生显著性变化,且低浓度组活性高于高浓度组;MDA浓度显著上升,并呈现出高浓度组大于低浓度组、小粒径组大于大粒径组的规律。不同浓度、粒径、暴露时间会对各项指标产生影响,四角蛤蜊鳃中MDA的浓度可作为未来评估海洋微塑料污染的可靠指标。

To determine the effects of microplastics on the physiological behavior and immune system activity of Mactra veneriformis,the effects of polystyrene(PS)exposure at different concentrations(1×10^(4) molecules/L and 1×10^(6) molecules/L)and particle sizes(1μm and 80 nm)on the filtration rate,respiration rate,malondialdehyde(MDA)content and impacts on activities of enzymes such as catalase(CAT),superoxide dismutase(SOD),acid phosphatase(ACP),alkaline phosphatase(AKP)were investigated.The results revealed that only the low concentration group of 1μm had a significant effect on the filtration rate;the respiration rate was significantly increased under exposure to large particles of polystyrene at high con-centrations.The activities of SOD and CAT both increased significantly in the early stages of the experiment and then de-creased.ACP activity increased significantly in the early stages and gradually decreased.The changes were not statistically significant.AKP activity changed significantly after 3 days,and the activity in the group exposed to low concentrations was higher than that of the group exposed to high concentrations.Moreover,MDA content significantly increased in the group exposed to high concentrations compared to the group exposed to low concentrations,and MDA content of the group ex-posed to small polystyrene particles increased compared to the group exposed to large particles.Different concentrations,particle sizes,and exposure times affected multiple physiological indicators.MDA content of M.veneriformis gills can be used as a reliable indicator to assess marine microplastic pollution.