微塑料对双酚A在鲤鱼肠道中累积及生长生理的影响

探明微塑料（MPs）对双酚A （BPA）在鱼类肠道中累积特征及鱼类生长生理的影响,本研究以黄河鲤鱼为模型生物,分析了0.5 μm聚苯乙烯微塑料（PS-MPs）与BPA联合作用下鲤鱼肠道中微塑料及BPA的累积特征、鲤鱼生长及其抗氧化酶活性,以及它们之间的响应关系。结果表明：联合处理下鲤鱼肠道中的PS-MPs含量随时间呈线性增加,且随投加的微塑料浓度增加而增加,而PS-MPs累积速率随时间呈先增加后减小趋势,其中在BPA+PS（L）处理（1 mg·L^-1 BPA+20 μg·L^-1 PS-MPs）下,0.25 d时鲤鱼肠道中PS-MPs累积速率达到峰值（373.81 μg·g^-1·d^-1）,BPA+PS（H）处理（1 mg·L^-1 BPA+100 μg·L^-1 PS-MPs）下,则是在0.125 d达到最高（644.00 μg·g^-1·d^-1）。与单一BPA暴露相比,联合暴露下鲤鱼肠道中BPA累积量增加,与BPA （1 mg·L^-1 BPA）处理相比,BPA+PS （L）和BPA+PS （H）处理下鲤鱼肠道中BPA含量分别提高了6.13%和9.74%,BPA累积速率分别增加了190.01%、373.80%。相较于对照处理,BPA处理和MPs与BPA联合处理均引起鲤鱼肠组织中超氧化物歧化酶（SOD）活性、过氧化氢酶（CAT）活性、还原型谷胱甘肽（GSH）含量、丙二醛（MDA）含量增加,使体质量下降幅度减缓,其中BPA、BPA+PS （L）和BPA+PS （H）处理下鲤鱼体质量（21 d）较对照处理分别下降1.22%、3.90%、4.33%。当微塑料投加量达到100 μg·mL^-1时,联合处理会增加鲤鱼肠道中SOD活性、CAT活性和GSH含量,抑制MDA产生,从而缓解MPs和BPA联合作用对鲤鱼造成的氧化损伤,并且减缓鲤鱼体质量下降。研究表明,微塑料的存在会增加双酚A在鲤鱼肠道中的累积,且两者联合作用对鲤鱼产生了协同毒理效应,导致鲤鱼生长速率减缓,体质量下降。

Effects of microplastics on accumulation and growth physiology of bisphenol A in the intestines of carps

To investigate the impact of microplastics（MPs）on the accumulation features and growth physiology of bisphenol A（BPA）in fish intestines, this study used yellow river carp as a model organism to analyze the accumulation characteristics, growth, and antioxidant enzyme activity of MPs and BPA in carp intestines under the combined action of 0.5 μm polystyrene microplastics（PS-MPs）and BPA, as well as the response relationship between them. The results show that the concentration of PS-MPs in carp intestines under the combined treatment increased linearly with time and with the concentration of added microplastics, while the rate of PS-MPs accumulation first increased and then decreased with time. Under the BPA+PS（L）（1 mg·L^-1 BPA+20 μg·L^-1 PS-MPs）treatment, the PS-MPs accumulation rate reached its peak（373.81 μg·g^-1·d^-1）at 0.25 d, and under the treatment of BPA+PS（H）（1 mg·L^-1 BPA+100 μg·L^-1 PS-MPs）, the accumulation rate reached its highest（644.00 μg·g^-1·d^-1）at 0.125 d. Compared with single BPA exposure, the BPA accumulation in carp intestines increased under the combined exposure. Compared with the treatment with only BPA（1 mg·L^-1 BPA）, the BPA concentrations in carp intestines increased by 6.13% and 9.74% under BPA+PS（L）and BPA+PS（H）treatments, respectively, and the BPA accumulation rates increased by 190.01% and 373.80%, respectively. Both BPA treatment and the combined action of MPs and BPA increased the activities of superoxide dismutase, catalase, reduced glutathione, and malondialdehyde content in carp intestinal tissues and slowed the decrease in body weight. Under the BPA, BPA+PS（L）, and BPA+PS（H）treatments, carp body weight decreased by 1.22%, 3.90%, and 4.33%, respectively, compared with the control treatment. When the amount of microplastics added reached 100 μg·mL^-1, the combined treatment increased the activity of superoxide dismutase, the content of catalase and glutathione in carp intestines, and inhibited the production of malondialdehyde, thereby alleviating the oxidative damage caused by the combined action of MPs and BPA and slowing down the decrease in carp body weight. The results showed that the presence of microplastics increased the accumulation of BPA in carp intestines, and the combined toxic effect of MPs and BPA led to a slowdown in carp growth rate and a decrease in body weight.