Effects of Aging and Air Pollution on Development of Pulmonayr Fibrosis and Emphysema.

目的：本课题旨在评价长期吸入道路灰尘和烟草烟雾与衰老效应在诱发慢性肺疾病如肺气肿和肺纤维化中的协同作用。方法：由于氧化-抗氧化失衡可能是导致肺实质损伤的机制并且肺中的抗氧化酶系统与人肺中的最相似，在该实验中使用8周龄的雄性仓鼠。饲养10周或46周后，在1 j周内分别暴露于烟草烟雾（S24，S60）和轮胎尘（D24，D 60）。另一组动物在14周内同时暴露于烟草烟雾和道路灰尘（SD 24）。在每组中研究了以下主题。1)离体肺的压力-容积（PV）曲线。2)肺泡壁的张力-张力关系。3)光学显微镜和电子显微镜观察的形态测定。4 ...更多信息 支气管肺泡灌洗（BAL）液的细胞分析。5)结果与讨论：年龄效应--P-V曲线随年龄增长无显著性差异。而L-T关系分析显示，随着年龄的增长，肺泡壁胶原和弹性纤维的质的变化导致肺泡壁的扩张性降低，肺泡壁的静息长度增加。这些结果表明，表面活性剂和肺泡壁的机械性能已随老化而改变。每一种随年龄增长的变化相互抵消，保持平衡，使整个肺的机械变化最小化。烟草烟雾暴露与衰老的关系--在老年肺中，烟草烟雾暴露（S_（60））引起静态顺应性增加，肺泡气腔扩大，肺泡壁胶原成分弹性下降。道路灰尘和烟草烟雾暴露的影响--D24和SD 2 j组的P-V曲线无显著性差异。在L-T曲线分析中，D24肺泡壁的弹性增加，胶原纤维的数量变化。SD 24肺泡壁的力学性质与人肺气肿相似，但胶原成分的质的变化使肺泡壁的扩张性减弱。D24的平均线性截距显著较小。这些结果表明，暴露于道路灰尘诱导肺组织的纤维化变化，暴露于道路灰尘和烟草烟雾两者诱导肺的肺气肿性变化。少

Purpose : this project aimed to evaluate the synergistic effects of the chronic inhalation of road dust and tobacco smoke and the aging effects to induce the chroniclung deseases, such as pulmonary emphysema and pulmonary fibrosis.Method : because oxidant-antioxidant inbalance might be a mechanism to induce the lung parenchymal injury and the antioxidant enzyme systems in the lung are most similar to that of the human lung, 8 weeks old male hamsters have been used in this experiment. after raising of 10 or 46 weeks, the animals were exposed to the tobacco smoke (S24, S60) and to the road dust by studded tire (D24, D60) during 1j weeks. the another group of the animals were exposed to the them both, the tobacco smoke and road dust, during the 14 weeks (SD24). the following subjects were studied in each groups. 1) pressure- volume (pv) curves of escised lung. 2) lengthy-tension (lt) relationships of alveolar wall. 3) morphometry of light-micrograh and electron-microscopic observations. 4 … More ) cellular analysis of broncho-alveolar lavage (bal) fluid. 5) collagen and elastin component of the lung tissue.Results and discussion : aging effect -- no significant difference was observed in the P-V curves with aging. but in the analysis of L-T relationship, the distensibility was decreased with aging by the qualitative changes of collagen and elastic fibers and resting length of alveolar wall was also increased with aging. these results suggest the mechanical properties of surfactant ant alveolar wall have been changed with aging. each changes with aging counteract to keep a balance to minimize the mechanical change of whole lung. effects of tobacco smoke exposure and aging -- in the aged lung, the tobacco smoke exposure (S60) brought about the increment of static compliance, the enlargement of alveolar air space and the decrease of elasticity of collagen component in the alveolar wall. effect of road dust and tobacco smoke exposure -- in both the group D24 and SD2j, there was no significant difference in P-V curves. in the analysis of L-T curves in D24, the elasticity of alveolar wall was increased by the quantitative changes of collagen fibers. the mechanical properthes of alveolar wall in SD24 showed less distensibility by the qualitative change of collagen component and was similar to that of pulmonary emphysema in the human lung. mean linear intercept was significantly smaller in D24. these results suggest that the exposure of road dust induces a fibrotic change of the lung tissue and the exposure of both, road dust and tobacco smoke ; induces an emphysematous changes of the lung with aging. Less