大气PM_(2.5)全身暴露对大鼠多脏器病理、氧化应激指标和炎症因子的影响

Effects of Atmospheric Fine Particulate Matter Whole Body Exposure on Pathology of Multiple Organs,Oxidative Stress Indicators and Inflammatory Factors in Rats

探讨太原市冬季大气细颗粒物(PM_(2.5))全身系统暴露对雄性SD大鼠5种脏器病理学、氧化应激及炎症反应的影响。于2018年11月至2019年1月于太原市采用IVC通气笼对大鼠进行大气PM_(2.5)的全身暴露染毒,分别染毒1个月和2个月;同时设立相应空气过滤对照组。采用HE染色方法观察大鼠肝、肾、脾、胃和小肠的组织病理学变化,并测定肝、肾、脾和胃的脏器系数;采用生化方法测定大鼠组织匀浆液中的超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量、白细胞介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)的水平。PM_(2.5)暴露后大鼠5种组织均体现出不同程度的病理学损伤,MDA含量与对照组相比显著增加。PM_(2.5)染毒使大鼠肝和肾的脏器系数比对照组显著增高;肾、脾、胃和小肠的SOD活性比相应对照组明显上升;肝和小肠的IL-6和TNF-α水平显著高于对照组。2个月暴露的损伤效应比1个月暴露更为严重。大气PM_(2.5)全身系统暴露(结合气态污染物)可导致大鼠多器官损害,且随着暴露时间延长而损害加重;肝、肾和小肠对PM_(2.5)刺激表现敏感。其机制可能与PM_(2.5)引起的组织MDA含量和炎症因子水平增加有关。

To investigate pathology,oxidative stress and inflammatory response of whole body exposure of ambient fine particulate matter(PM_(2.5))in winter of Taiyuan in China in five organs of male SD rats in this study,rats were exposed to airborne PM_(2.5)using a whole-body inhalation system(individual ventilated cage(IVC)exposure system)for 1 month and 2 months respectively from November^(2)018 to January 2019 in Taiyuan.Meanwhile,the corresponding control groups(filter air groups)were respectively established.The histopathological changes of liver,kidney,spleen,stomach and small intestine in rats were observed by hematoxylin-eosin(HE)staining,and the organ coefficients of liver,kidney,spleen and stomach were measured.The levels of superoxide dismutase(SOD),malondialdehyde(MDA),interleukin-6(IL-6)and tumor necrosis factor-α(TNF-α)in rat tissue homogenates were determined by biochemical methods.PM_(2.5)exposure caused pathological damage in varying degrees in five organs in rats,and significantly increased MDA contents compared with the corresponding controls.Organ coefficients of liver and kidney in rats exposed to PM_(2.5)were raised relative to the controls.The SOD activities of the kidney,spleen,stomach and small intestine were significantly higher than that of the controls.The levels of IL-6 and TNF-αin the liver and small intestine were obviously elevated compared to the controls.The injury effects of 2-month exposure were more severe than that of 1-month exposure.Whole body exposure to atmospheric PM_(2.5)(combined with gaseous pollutants)caused multiple organ damage in rats,and such injury aggravated with the prolonged exposure time.Liver,kidney and small intestine were sensitive to PM_(2.5)stimulation.Increases of MDA contents and inflammatory factor levels might implicate in the impairment of multiple murine organs induced by PM_(2.5).