PM2.5 samples were sampled and PM2.5 saline suspension was prepared,the male SD rats were injected with the suspension.The rats were administered using PM2.5 solutions by intratracheal instillation respectively every three days enduring for 60 days.The histopathological changes and the mRNA and protein expressions of inflammatory factors and CK-18 in lung of rats were detected.The results showed that with the PM2.5 dosage increasing,the lung histopathological damage was aggravated accompanied by some inflammatory responses like hyperemia and inflammatory cell infiltrate.Such the effects induced by winter PM2.5 were significant compared to summer PM2.5.The mRNA and protein expressions of TNF-α、IL-6、TGF-β and CK-18 in the lung tissues in medium and high dose PM2.5groups in winter were significantly increased compared with the control group,while the expressions of the above 4 genes were significantly elevated in the high dose PM2.5 group in summer compared to the control.It suggests that subchronic exposure of PM2.5 induces an increase of levels of inflammatory related factors,which may enhance the inflammatory responses in lung.Up-regulation of CK-18 expression suggests that the lung is in the status of oxidative stress induced by PM2.5.The inflammatory responses in the lungs of rats caused by winter PM2.5 in Taiyuan were more severe than that of summer PM2.5.%研究采集PM2.5样本,制备PM2.5生理盐水混悬液,对雄性SD大鼠进行染毒实验,检测大鼠肺组织病理学改变,测定肺中炎症因子和CK-18 mRNA和蛋白表达.结果显示,随着PM25染毒剂量增加,肺组织出现肺充血和炎性细胞浸润等炎症反应,冬季PM2.5所致肺病理学损伤比夏季严重.冬季PM2.5中、高剂量组和夏季高剂量组大鼠肺中TNF-α、IL-6、TGF-β、CK-18 mRNA和蛋白表达比对照组显著增加.这说明PM2.5亚慢性染毒可增加炎症因子表达水平,促进肺炎症反应.CK-18表达上调提示PM2.5致肺组织处于氧化应激状态.太原市冬季PM2.5引起大鼠肺炎症损伤效应比夏季严重.
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