Molecular and Genetic Laboratory, College of Life Science, Henan Normal University, 46# East of Construction Road, Xinxiang 453007, Henan, China.
Molecular and Genetic Laboratory, College of Life Science, Henan Normal University, 46# East of Construction Road, Xinxiang 453007, Henan, China.
Sci Total Environ. 2020 May 10;716:136479. doi: 10.1016/j.scitotenv.2019.136479. Epub 2020 Jan 7.
The occurrence and accumulation of microplastics in wildlife and humans have become a serious global scale concern over the last decade. To evaluate the potential toxic effects of PVC (polyvinyl chloride) microplastics in freshwater fish larvae, we conducted chronic 30-day and 60-day dietary exposure using Cyprinus carpio var. larvae. We exposed the larvae to four treatments with different microplastic concentrations (10%, 20%, and 30%) using food rationed diets, in conjunction with a non-plastic control. The results indicated that microplastics significantly inhibited weight gain and growth under all PVC treatments, compared to the control group. SOD (superoxide dismutase) and CAT (catalase) activities were analyzed, and an inverse relationship between them was observed. The activities of GPx (glutathione peroxidase) initially ascended and then descended with increased PVC concentrations following 30 days of exposure. A dose dependent downtrend was observed after 60 days of exposure. Malondialdehyde (MDA) levels were significantly reduced upon exposure to different concentrations of microplastics in various tissues. Altered antioxidant-related gene expression was observed in the livers of larvae exposed to the PVC microplastics. The transcription of CYP1A and GSTa initially increased, and then decreased under higher microplastics concentrations following 30 days of exposure. Furthermore, histological studies revealed cytoplasmic vacuolation in the liver under exposure to 20% and 30% microplastics. This investigation provided basic toxicological data toward elucidating and quantifying the impacts of PVC microplastics on freshwater organisms.
在过去的十年中，野生动物和人类体内微塑料的出现和积累已成为一个严重的全球性问题。为了评估聚氯乙烯（PVC）微塑料对淡水鱼类幼体的潜在毒性影响，我们使用鲤鱼幼体进行了为期 30 天和 60 天的慢性饮食暴露实验。我们通过饲料定量喂养的方式，用不同浓度（10%、20%和 30%）的微塑料处理幼鱼，同时设置不含塑料的对照组。结果表明，与对照组相比，所有 PVC 处理组的微塑料都显著抑制了幼鱼的体重增加和生长。分析了 SOD（超氧化物歧化酶）和 CAT（过氧化氢酶）的活性，发现它们之间呈反比关系。暴露 30 天后，随着 PVC 浓度的增加，GPx（谷胱甘肽过氧化物酶）的活性先上升后下降。暴露 60 天后，观察到剂量依赖性下降趋势。不同浓度微塑料暴露后，各组织中的 MDA（丙二醛）水平均显著降低。暴露于 PVC 微塑料的幼鱼肝脏中观察到抗氧化相关基因表达发生改变。暴露 30 天后，CYP1A 和 GSTa 的转录水平先升高，然后在较高的微塑料浓度下下降。此外，组织学研究显示，暴露于 20%和 30%微塑料时，肝脏出现细胞质空泡化。本研究提供了基本的毒理学数据，有助于阐明和量化 PVC 微塑料对淡水生物的影响。
