大气中细颗粒物及其铁元素对大鼠肺损伤的影响

Effects of Fine Particulate Matter and Its Iron in the Atmosphere on Lung Injury in Rats

氧化应激和炎症反应被广泛地认为是PM2.5(大气细颗粒物)对肺部的作用方式。然而具体哪种PM2.5的组分在PM2.5引起肺损伤时发挥重要作用却研究较少。因此,将不同浓度的PM2.5(0.5 mg/kg,3.0 mg/kg和15.0 mg/kg体重)和Fe^3+(22.5μg/kg,112.5μg/kg和562.5μg/kg体重)通过气管滴注的方式暴露于大鼠来探究PM2.5中的Fe元素对大鼠肺部的损伤。处死大鼠后获取大鼠的支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF)和肺组织,使用ELISA、比色法和HE染色来检测大鼠BALF中促炎因子白细胞介素-6(interleukin-6,IL-6)、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、肺组织中氧化应激指标超氧化物歧化酶(superoxide dismutase,SOD)、丙二醛(malondialdehyde,MDA)以及观察大鼠肺组织的病理变化。结果表明,PM2.5以及Fe^3+浓度的升高能够显著抑制SOD活性并增加MDA、IL-6、TNF-α水平,但是在同等含量的铁元素的情况下(PM2.5高剂量组和Fe^3+中剂量组),PM2.5对大鼠的损伤更为严重。因此,PM2.5及其Fe元素可以引起大鼠肺部的损伤,在这一过程中Fe元素发挥重要作用,但是PM2.5对大鼠的肺损伤应由多种组分协同完成。

PM2.5(fine particulate matter)induces pulmonary inflammation via oxidative stress,and this role in the lungs is widely accepted,but there are few studies on which PM2.5 components play an important role in PM2.5-induced lung injury.Therefore,in order to investigate the damage of the Fe element in PM2.5 to the lungs of rats,different concentrations of PM2.5(0.6 mg/kg,3.0 mg/kg and 15.0 mg/kg body weight)and Fe^3+(22.5μg/kg,112.5μg/kg and 562.5μg/kg body weight)were exposed to rats by tracheal instillation.After the rats were sacrificed,the bronchoalveolar lavage fluid(BALF)and lung tissues of the rats were obtained.ELISA(enzyme linked immunosorbent assay),colorimetry and HE staining were used to detect pro-inflammatory factors interleukin-6(IL-6),tumor necrosis factor-α(TNF-α)in rat BALF,oxidative stress indicators superoxide dismutase(SOD),malondialdehyde(MDA)and pathological changes in rat lung tissues.The results show that the increase of PM2.5 and Fe^3+concentration can significantly inhibit SOD activity and increase the levels of MDA,IL-6 and TNF-α,but in the case of the same amount of iron(PM2.5 high dose group and Fe^3+medium dose group),PM2.5 damage to rats more severely.Therefore,PM2.5 and its Fe element can cause damage to the lungs of rats.During this process,Fe element plays an important role,but the lung damage of PM2.5 on rats should be coordinated by various components.