MECHANISM OF AIR POLLUTANT INDUCED AIRWAY PERMEABILITY

拟议中的研究将调查a)控制呼吸道的机制。 渗透性，b)吸入后早期损伤的细胞内部位 大鼠暴露于03和N02和c)意味着阻止或逆转污染物 导致通透性增加。 我们实验室的初步研究表明，气管和 吸入后支气管肺泡对大分子的通透性 大鼠暴露于03。渗透性的增加似乎导致在 至少在一定程度上，来自紧密连接的微扰。基于我们的 肌动蛋白和肌球蛋白在人体内分布的初步观察 纤毛虫顶端细胞质和紧密连接附近 也基于上皮细胞在动作上的相似性 关于污染气体和破坏细胞骨架的药物，我们建议 细胞骨架可能是污染物的胞内靶点， 它在密结磁导率的调制中起着关键作用。 我们还预测了细胞骨架在囊泡运输中的作用。 航空公司和其他系统一样。拟议的研究考虑到了 细胞骨架活性药物与污染气体和 有可能通过药物逆转污染效应。各种各样的 将分析各项指标，以实现预期目标。 大鼠将暴露在0.2-0.8ppm的臭氧或5-25ppm的NO2中。通过以下方式进行治疗 细胞骨架失稳(秋水仙素和细胞松弛素B)或稳定化 (蝴蝶素和激动素)药物将单独或在 与污染物暴露相结合。粘膜通透性的变化 大分子(摩尔重量469到69,000)将使用同位素进行跟踪 在这个实验室介绍的标签程序大约有两个 几年前就有了，现在已经很成熟了。分子运输动力学 在不同的实验条件下将进行比较。 光镜和电子显微镜的免疫细胞化学将用于 描述各种细胞骨架成分及其与 通过紧密连接或内吞小泡运输。冷冻骨折 将对复制品进行形态计量学分析，以检测紧密连接的细微变化 药物治疗后的连接深度和膜内链 污染物暴露。上皮细胞的表面形态，损伤 细胞膜和细胞间隙的形成 邻近细胞的缩回将被监测购买扫描电子 显微镜。

The proposed study will investigate a) mechanisms which control airway permeability, b) intracellular sites of early injury following inhalation exposure of rats to 03 and N02 and c) means to block or reverse pollutant induced increased permeability. Pilot studies from our laboratory demonstrate an increase in tracheal and bronchoalveolar permeability to macromolecules following inhalation exposure of rats to 03. The increased permeability appears to result, at least in part, from the perturbation of tight junctions. Based on our preliminary observations on the distribution of actin and myosin in the apical cytoplasm and in close vicinity of tight junctions of ciliated epithelial cells and also based on the similarities in the actions of pollutant gases and cytoskeleton-disrupting drugs, we propose that the cytoskeleton is a likely intracellular target site for pollutant and that it plays a critical role in the modulation of tight junction permeability. We also anticipate the role of cytoskeleton in vesicular transport in airways as in other systems. The proposed studies take into account an extensive comparison of cytoskeleton-active drugs with pollutant gases and possible reversal of pollutant effects by the drugs. A variety of indicators will be analyzed to achieve the projected goals. Rats will be exposed to 0.2-0.8 ppm O3 or 5-25 ppm NO2. Treatments with cytoskeleton-destabilizing (colchicine and cytochalasin B) or stabilizing (Phalloidin and kinetin) drugs will be carried out either alone or in combination with pollutant exposures. Changes in mucosal permeabilities to macromolecules (mol wt 469 to 69,000) will be followed using isotope labeling procedures which were introduced in this laboratory about two years ago and are now well established. Kinetics of molecular transport under various experimental conditions will be compared. Immunocytochemistry by light and electron microscopy will be employed to characterize various cytoskeletal components and their relation to transport through tight junctions or endocytic vesicles. Freeze fracture replicas will be analyzed morphometrically to detect fine changes in tight junctional depth and intramembranous strands following drug treatments or pollutant exposures. Surface morphology of epithelial cells, injuries to cell membranes and formation of intercellular spaces resulting from retraction of adjacent cells will be monitored buy scanning electron microscopy.