Department of Clinical Medicine, Centre for Nutrition, University of Bergen, Bergen, Norway.
Department of Clinical Medicine, Centre for Nutrition, University of Bergen, Bergen, Norway.
Toxicol Lett. 2022 Nov 1;370:35-41. doi: 10.1016/j.toxlet.2022.09.002. Epub 2022 Sep 8.
Microplastic particles are ubiquitous in the environment. However, little is known about their uptake and effects in humans or mammalian model organisms. Here, we studied the effects of pristine polyamide (15-20 µm) and polyethylene (40-48 µm) particles after oral ingestion in rats. The animals received feed containing microplastic particles (0.1% polyamide or polyethylene, or a mixture of both polymers) or a control diet without microplastic particles, for 5 weeks. The permeability of the duodenum was investigated in an Ussing chamber, whereas gene expression and concentration of tight junction proteins were measured in gut tissue and plasma. Microplastic particles were quantified by pyrolysis-gas chromatography/mass spectrometry in rats' feces. Rats fed with microplastic particles had higher duodenal permeability. Expression of gene coding for the tight junction protein occludin (OCLN) was higher in PE treated animals compared to control or the PA group. No changes in the expression of the gene coding for zonula occludens protein 1 were detected. Occludin protein concentrations were below the limit of detection of the applied method in both gut and plasma. Zonula occludens protein 1 concentrations in the gut were significantly higher in groups exposed to PA and PE as compared to control, while zonula occludens protein 1 concentrations in plasma did not show significant changes. These results demonstrated that short-term exposure to a dose of 0.1% (w/w) microplastic particles in feed had limited effects on duodenal permeability, expression of pro-inflammatory protein genes and tight junction protein genes in the duodenum.
微塑料颗粒在环境中无处不在。然而，人们对其在人类或哺乳动物模式生物中的摄取和作用知之甚少。在这里，我们研究了口服摄入原始聚酰胺（15-20μm）和聚乙烯（40-48μm）颗粒后的大鼠的影响。动物接受含有微塑料颗粒（0.1%聚酰胺或聚乙烯，或两种聚合物的混合物）的饲料或不含微塑料颗粒的对照饲料，为期 5 周。在 Ussing 室中研究了十二指肠的通透性，而肠道组织和血浆中的紧密连接蛋白的基因表达和浓度则进行了测量。通过热解气相色谱/质谱法在大鼠粪便中定量微塑料颗粒。用微塑料颗粒喂养的大鼠十二指肠通透性更高。与对照组或 PA 组相比，PE 处理动物中编码紧密连接蛋白 occludin（OCLN）的基因表达更高。未检测到编码封闭蛋白 1 的基因表达发生变化。在肠道和血浆中，occludin 蛋白浓度均低于应用方法的检测限。与对照组相比，暴露于 PA 和 PE 的组中肠道中的封闭蛋白 1 浓度显著更高，而血浆中的封闭蛋白 1 浓度没有明显变化。这些结果表明，短期摄入饲料中 0.1%（w/w）微塑料颗粒剂量对十二指肠通透性、十二指肠中促炎蛋白基因和紧密连接蛋白基因的表达影响有限。
