大气污染物对大鼠肺细胞毒性及病理学研究

Study on pulmonary cell toxicity and pathology in rats exposed to air pollutants

目的 探讨大气污染物对大鼠肺细胞毒性及病理学改变。方法 80只Wistar大鼠 (体重 180～ 2 2 0 g)随机分为 4组 ,即对照组和实验组 (低、中、高剂量组 ) ,分别进行总悬浮颗粒物 (TSP)和SO2 、NO2 染毒。TSP染尘采用气管注入法 ,实验组分别注入TSP(7 5 ,15 ,30mg)生理盐水混悬液 1ml,对照组注入 1ml生理盐水。染尘后第 2d ,实验组静式吸入含SO2 和NO2 的空气混合气 ,SO2 的浓度分别为 8,16 ,32mg/m3 ;NO2 浓度分别为 5 ,10 ,2 0mg/m3 ,对照组吸入一般空气。连续染毒 7d后 ,计数支气管肺泡灌洗液 (BALF)中WBC总数、嗜酸细胞 (Eos)数及细胞分类 ,电镜下观察肺组织超微结构变化。结果 高剂量组WBC总数显著高于对照组 (P <0 0 5 ) ;随着剂量的增加 ,肺泡壁增厚明显 ,高剂量组出现肺间质结缔组织增生、泡壁不光滑及肺泡融合。结论 大气污染物可导致肺组织发生急性炎症 ,呼吸面积极度变小 ,并有早期硬化改变。

Objective To explore pulmonary cell toxicity and patholog ical change in rats exposed to air pollutants. Methods 80 Wistar rats (180-220g weight) were randomly di vided into 4 groups,which were control group and treated groups (low,middle and high dose groups).Treated rats were respectively exposed to TSP of 7.5,15 or 30 mg in 0.85%NaCl of 1ml by intratracheal instillation,and then were exposed to S O\- 2,NO\-2 of 8,5;16,10 or 32,20 mg/m\+3 by statically for 7 days.0.85%NaCl of 1ml was instilled and general air was inhaled by rats of control group.The counts of WB C and Eos as well as the sorts of WBC in BALF were measured.The changes of ultra microscopic structure in lungs were observed under electron microscope. Results The count of WBC in high dose group was significa ntly higher than that in control group(P<0.05).The thickness of alveoli wall w as increased with increased dose.There was hyperplasia of connective tissue in p ulmonary interstitial.Non-smooth in alveoli wall and combined alveoli were obser ved.Conclusion Air pollutants could induce acute inflammation in lungs and decrease respiratory area.And early fibrosis may occur.