Stevens M A, Ménache M G, Crapo J D, MIller F J, Graham J A
Northrop Services, Inc.-Environmental Sciences, Research Triangle Park, North Carolina 27709.
J Toxicol Environ Health. 1988;23(2):229-40. doi: 10.1080/15287398809531109.
Pulmonary function was examined for juvenile and young adult Fischer 344 rats that were continuously exposed to NO2 (0.5, 1.0, or 2.0 ppm) for up to 6 wk. The exposure included twice daily 1-h spikes equal to 3 times the baseline concentration. This spike-to-baseline ratio was chosen to simulate morning and evening urban rush-hour conditions. Juvenile rats were examined after 3 and 6 wk of NO2 exposure, whereas young adult rats were examined after 1-, 3-, and 6-wk intervals. Lung volumes, compliance, and efficiency of ventilation distribution were evaluated. Lung volumes increased in the juvenile rats after 3- and 6-wk exposures to 1.0 and 2.0 ppm NO2, but were unchanged in young adult rats. Lung compliance increased in juvenile rats exposed to 1.0 or 2.0 ppm NO2 for 3 wk. However, it was unchanged in juvenile rats exposed for 6 wk or in young adult rats exposed for 1 or 3 wk. Compliance decreased in young adult rats exposed to 2.0 ppm NO2 for 6 wk and was correlated to an overall thickening of alveolar interstitium and septal tissue. However, the observed changes in pulmonary function were marginal and reversible, since lung-function measurements were not different from controls after a 3-wk recovery period.
对幼年和年轻成年的Fischer 344大鼠进行肺功能检查，这些大鼠连续6周暴露于二氧化氮（0.5、1.0或2.0 ppm）环境中。暴露过程包括每天两次1小时的浓度峰值，峰值浓度为基线浓度的3倍。选择这种峰值与基线浓度之比是为了模拟早晚城市高峰时段的情况。幼年大鼠在二氧化氮暴露3周和6周后进行检查，而年轻成年大鼠在1周、3周和6周的间隔后进行检查。评估了肺容量、顺应性和通气分布效率。幼年大鼠在暴露于1.0和2.0 ppm二氧化氮3周和6周后肺容量增加，但年轻成年大鼠的肺容量没有变化。暴露于1.0或2.0 ppm二氧化氮3周的幼年大鼠肺顺应性增加。然而，暴露6周的幼年大鼠或暴露1周或3周的年轻成年大鼠的肺顺应性没有变化。暴露于2.0 ppm二氧化氮6周的年轻成年大鼠肺顺应性降低，且与肺泡间质和间隔组织的整体增厚相关。然而，观察到的肺功能变化很小且是可逆的，因为在3周的恢复期后，肺功能测量值与对照组没有差异。
