急性、慢性臭氧暴露对小鼠肺部炎症、肺部结构和肺功能的影响

The Effects of Acute and Chronic Ozone Exposure on Inflammation,Structure and Function in Murine Lung

目的探讨急性、慢性臭氧暴露对小鼠肺部炎症、肺部结构和肺功能的影响。方法 32只C57/BL6小鼠随机分为单次(急性)臭氧暴露组、单次空气暴露组、多次(慢性)臭氧暴露组(1次/3 d,6周)和多次空气暴露组,每组8只。小鼠暴露于2.5 ppm的臭氧环境中,3 h/次。于臭氧暴露结束后24 h,评估肺容积和低密度区(LAA)比例、肺功能、支气管肺泡灌洗液(BALF)细胞计数、BALF丙二醛(MDA)、血清8-脱氧鸟苷(8-OHdG)、肺部炎症积分以及肺组织平均内衬间隔(Lm)。结果与单次空气暴露组比较,单次(急性)臭氧暴露增加BALF炎症细胞总数,增加肺部炎症积分,增加BALF中MDA水平、血清8-OHdG水平,不影响肺容积、肺容积中LAA比例、肺总量、呼吸气流、肺部Lm。与单次(急性)臭氧暴露组、单次空气暴露组、多次空气暴露组比较,多次(慢性)臭氧暴露增加BALF炎症细胞总数,增加肺容积、肺容积中LAA比例,增加肺总量,介导呼出气流阻塞,增加肺部炎症积分和Lm。结论急性臭氧暴露诱导气道/肺部炎症和氧化应激,慢性臭氧暴露诱导气道/肺部炎症、肺气肿和呼出气流阻塞。

Objective To investigate the effects of acute and chronic ozone exposure oninflammation, structure and function in murine lung.Methods 32 C57/BL6 mice were randomly dividedinto a single （ acute） ozone exposed group, a single air exposed group, a multiple （ chronic） ozone exposedgroup （ every three days over 6 weeks） , and a multiple air exposed group with 8 mice in each group. Themice were exposed to 2.5 ppmof ozone or air for 3 hours per time and sacrificed 24 hours after the last timeof ozone exposure. Lung volume, low attenuation area （ LAA） percentage, lung function, cell counts andmalondialdehyde （ MDA） in bronchoalveolar lavage fluid （ BALF） , 8-hydroxy-2′-deoxyguanosine （ 8-OHdG）in serum, inflammation scores and mean linear intercept （ Lm） in lung section were assessed.Results Compared with the single air exposed group, single （ acute） ozone exposure led to increases in inflammatorycells in BALF, inflammation scores in the lung tissue,MDA in BALF and 8-OHdG in serum, but had no effecton lung volume, LAA percentage, airflow or Lm. Compared with the single （ acute） ozone exposed group, thesingle air exposed group and the multiple air exposed group, multiple （ chronic） ozone exposure increasedinflammatory cells in BALF, lung volume, LAA percentage, total lung capacity and lung compliance, mediatedairflow obstruction, and also increased lung inflammation socres and Lm.Conclusion Acute ozone exposureinduced airway/ lung inflammation and oxidative stress, while chronic ozone exposure induced airway/lunginflammation, emphysema and airflow obstruction.