空气污染暴露对大鼠呼吸系统炎症反应的影响及机制研究

Effect of Air Pollution Exposure on Inflammatory Reaction of Respiratory System in Rats and Its Mechanism

目的探讨空气污染暴露对大鼠呼吸系统炎症反应的影响及机制研究。方法27只雄性SD大鼠随机分为洁净组、大气组及过滤组,每组9只。洁净组放置于SPF动物房内饲养,大气组放置在实时收集外界环境空气的饲养舱内,过滤组大鼠放置在可经HEPA滤膜过滤掉空气动力学直径>0.3μm的细颗粒物的饲养舱中。暴露时间为2016年12月1日—2017年2月28日。暴露结束后,将各组大鼠经右侧主支气管行支气管肺泡灌洗,收集支气管肺泡灌洗液(BALF),检测T淋巴细胞亚群和炎性因子水平;并观察肺组织病理学变化。结果与洁净组比较,过滤组和大气组大鼠肺组织出现肺间隔增宽,炎性细胞浸润,部分肺泡融合形成肺大泡,且大气组炎症程度较过滤组加重。与洁净组比较,过滤组和大气组BALF中CD8+水平升高,CD4+/CD8+水平降低(P<0.05,P<0.01),但过滤组和大气组间比较差异均无统计学意义(P>0.05)。与洁净组比较,过滤组和大气组大鼠BALF中白细胞介素-1β(IL-1β)、IL-6、IL-13、IL-17、肿瘤坏死因子-α水平均升高(P<0.01),但过滤组与大气组上述指标比较差异无统计学意义(P>0.05)。结论空气质量不良可引起大鼠肺组织炎症反应,与肺组织中炎性因子水平升高和T淋巴细胞构成异常有关,这种影响可能与空气中的气体污染物和颗粒污染物均有关系。

Objective To investigate the effect of air pollution exposure on inflammatory reaction of respiratory system in rats and its mechanism.Methods A total of 27 male SD rats were randomly divided into specific pathogen free(SPF)group(n=9),atmosphere group(n=9)and filtration group(n=9).SPF group was bred in SPF-class lab,while atmosphere group was bred in an animal cage filled with real-time collection of outdoor air,and filtration group was bred in an cage in which fine particle with aerodynamic diameter greater than 0.3μm had been filtered out through the HEPA filter membrane.The exposure period was from December 1,2016 to February 28,2017.At the end of exposure,the rats were subjected to bronchoalveolar lavage through the right main bronchus,and bronchoalveolar lavage fluids(BALF)were collected,and then levels of T lymphocyte subset and inflammatory factors were detected in each group.Pathological changes of lung tissues were observed.Results Compared with those in SPF group,lung tissues showed a widening septum between lungs and inflammatory cell infiltration with some alveoli fused to pulmonary bullae in filtration group and atmosphere group,and the degree of inflammation in atmosphere group was more severe than that in filtration group.Compared with those in SPF group,levels of CD8+were significantly increased,while levels of CD4+/CD8+were significantly decreased in the BALF in filtration group and atmosphere group(P<0.05,P<0.01),but there were no statistically significant differences in the levels between filtration group and atmosphere group(P>0.05).Compared with those in SPF group,levels of interleukin(IL)-1β,IL-6,IL-13,IL-17 and tumor necrosis factor-αwere significantly increased in BALF in filtration group and atmosphere group(P<0.01),but there were no statistically significant differences in the levels between filtration group and atmosphere group(P>0.05).Conclusion Poor air quality may lead to inflammatory reactions in lung tissues of rats,which is related to the increased levels of inflammatory factors and the abnormal composition of T lymphocytes in lung tissues.This effect may be related to both gas pollutants and particulate pollutants in the air.