大气可吸入颗粒物对大鼠气道的致炎症作用研究

目的 探讨城市大气颗粒污染物（PM10）对大鼠肺脏的毒性作用，并为进一步研究PM10在诱发大鼠哮喘中的作用筛选敏感指标提供依据。方法 用MODEL－120A型大容量采样器采集北京市城区颗粒物PM10，进行大鼠气管两次注入染毒。结果 染毒大鼠支气管肺沟灌洗液（BALF）中细胞总数、酸性磷酸酶（ACP）、碱性磷酸酶（AKP）活性及丙二醛（MDA）的含量均有升高，谷胱甘肽－过氧化物酶（GSH－PX）活性降低，并有剂量－反应关系。PM10染毒组大鼠肺匀浆上清液中ACP、GSH－Px活性与对照组比较仅在高剂量组中差异有显著性意义（P＜0.0）。病理切片显示，PM10可引起肺泡及细支气管结构损伤，肺间质炎性细胞侵润，嗜酸性粒细胞浸润明显增多，并随染毒剂量增加炎性损伤作用加重。PM10有自由基活性并可引起大鼠气道急性炎症反应。结论 ACP、GSH－Px可作为检测PM10对大鼠气道炎性损伤的敏感指标。

Effects of inhalable particle matters on airway inflammation of rats

Objective In order to study the mechanism of the airway inflammation induced by the inhalable particle matter (PM 10 ),the toxicity effects of PM-{10} collected from Beijing urban area on rat's airway were assessed by intratracheal instillation.Methods PM-{10} was collected by MODEL 120A in Beijing urban areas.After rats were treated by PM-{10} twice,samples were obtained.Results The total number of inflammatory cells,the concentration or activities of acid phosphatase (ACP),alkaline phosphatase (AKP) and malondiadehyde (MDA) in BALF in PM-{10} treated groups were increased in a dose respondent manner,while glutathion peroxidase (GSH Px) was decreased compared with control group.The activities of ACP and GSH Px in lung homogenate of the highest doses group were significantly different from that in control group.The results of histopathological analysis indicated that PM-{10} can cause airway injury and pathological changes,such as the damage of alveolar septum,bronchial epithelium in a dose dependent way.The infiltration of inflammatory cells in lung matrix,especially eosinophilia was observed.These studies suggested that PM-{10} had free radical activity and caused lung inflammation and epithelial injury.Conclusion ACP and GSH PX may be considered as sensitive indicatior of toxic effect of PM-{10} on rat's airway inflammation.