大气混合污染物对大鼠细胞因子水平及超微结构的影响

Effect on cytokines and ultrastructure in rats exposed to mixed air pollutants

目的：探讨大气污染对大鼠细胞因子水平及超微结构的影响。方法：将48只Wistar大鼠（体重180—220g）随机分为6组，即3个对照组和3个实验组，分别进行可吸入颗粒物（PM10）和CO、SO2、NO2染毒。PM10染尘采用气管注入法，实验组注入PM10（22．5mg／m1）生理盐水混悬液1ml，对照组注入1rnJ生理盐水。染尘后第2d，实验组静式吸入含SO2、NO2和CO的空气混合气，浓度分别为22．5、18、600mg／m^3，对照组吸入正常空气。于吸入气体污染物1d、15d、30d后，测定支气管肺泡灌洗液（BALF）中细胞因子水平，电镜下观察气管、肺组织超微结构变化。结果：实验组大鼠BALF中细胞因子水平显著高于对照组（P〈0．05）；随着染尘染毒时间的增加，气管纤毛结构破坏，气管及肺组织发生炎症反应，伴有早期硬化改变。结论：大气混合污染物可导致大鼠BALF中细胞因子水平增高，肺组织发生急性炎症，并有早期硬化改变，细胞因子改变可作为大气污染对机体危害的敏感指标之一。

Objective： To explore the effects of mixed air pollutants on the levels of cytokines and uhrastructure in lungs of rats. Methods： 48 Wistar rats （180 -220g） were randomly divided into 3 tested groups and 3 control groups. Rats in tested groups were respectively exposed to PM10 of 22.5mg in 1 ml saline by intratracheal instillation, and then were respectively exposed to mixed gas of SO2, NO2, and CO by static inhalation 2h per day for ld, 15d and 30d respectively, lml saline was instilled and general air was inhaled in rats of control group. The levels of cytokines in bronchoalveolar lavage fluid （BALF） were measured by ELISA. The bronchial and pulmonary uhrastructure were observed under electron microscope. Results： The results showed that the levels of cytokine in BALF were significantly higher in tested groups than those in control groups （ P 〈0. 05 ）. With the exposed time increased, loss of bronchial fiber waver appeared. Acute flammation in bronchi and lung appeared, then respiratory area decrease and early fibrosis occured. Conclusions： The mixed air pollutants could lead to the increased levels of cytokines in BALF and lung injury. The changes of cytokine level could evaluate the body damage caused by air pollution as a sensitive standard.