van Bree L, Marra M, Rombout P J
Department of Inhalation Toxicology, National Institute of Public Health and Environmental Protection, Bilthoven, The Netherlands.
Toxicol Appl Pharmacol. 1992 Oct;116(2):209-16. doi: 10.1016/0041-008x(92)90300-h.
Rats and guinea pigs were exposed to 0.8 mg ozone (O3)/m3 (approximately 0.4 ppm) for 12 hr during the daytime, 12 hr during the nighttime, or continuously to investigate circadian variation in O3-induced pulmonary toxicity during single and repeated O3 exposures. Biomarkers in bronchoalveolar lavage (BAL) fluid and lung tissues were measured as indicators of biochemical and inflammatory responses. Nighttime O3 exposure of rats resulted in larger increases of protein, albumin, and inflammatory cells in BAL fluid compared to those after daytime O3 exposure and this daytime-nighttime difference was statistically significant (p < 0.05). Single daytime or nighttime O3 exposure of guinea pigs resulted in comparable increases of BAL fluid proteins and inflammatory cells without a daytime-nighttime difference. Nighttime and continuous O3 exposure of rats for 3 days resulted in comparable increases in lung antioxidant enzyme activities, both of which differed statistically from effects from daytime O3 exposures (p < 0.05). Continuous O3 exposure of guinea pigs for 3 days caused, in general, statistically larger increases in lung tissue parameters compared to nighttime O3 exposures (p < 0.05). These results suggest that the extent of O3-induced acute pulmonary biochemical and inflammatory responses is directly related to the level of physical and respiratory activity. For rats, effects from continuous O3 exposure appear to be controlled by the nighttime, physically active period. In guinea pigs, the comparable responses following daytime or nighttime O3 exposure seem in accordance with their random behavioral daily activity pattern. This study supports the view that physical activity-related increases in inhaled dose significantly enhance the pulmonary O3 responses.
将大鼠和豚鼠暴露于0.8毫克臭氧（O₃）/立方米（约0.4 ppm）的环境中，分别在白天暴露12小时、夜间暴露12小时或持续暴露，以研究单次和重复暴露于臭氧期间，臭氧诱导的肺毒性的昼夜变化。测量支气管肺泡灌洗（BAL）液和肺组织中的生物标志物，作为生化和炎症反应的指标。与白天臭氧暴露后相比，夜间臭氧暴露的大鼠BAL液中蛋白质、白蛋白和炎症细胞的增加幅度更大，且这种白天与夜间的差异具有统计学意义（p < 0.05）。豚鼠单次白天或夜间臭氧暴露后，BAL液中蛋白质和炎症细胞的增加幅度相当，不存在白天与夜间的差异。大鼠夜间和持续3天的臭氧暴露导致肺抗氧化酶活性的增加幅度相当，两者与白天臭氧暴露的影响在统计学上均有差异（p < 0.05）。豚鼠持续3天的臭氧暴露，总体上导致肺组织参数的增加在统计学上比夜间臭氧暴露更大（p < 0.05）。这些结果表明，臭氧诱导的急性肺生化和炎症反应程度与体力和呼吸活动水平直接相关。对于大鼠，持续臭氧暴露的影响似乎受夜间活跃期的控制。对于豚鼠，白天或夜间臭氧暴露后的类似反应似乎与其随机的日常行为活动模式一致。本研究支持这样的观点，即与体力活动相关的吸入剂量增加会显著增强肺部对臭氧的反应。
