IN VITRO TOXICITY OF AIRBORNE POLLUTANTS AND CHEMICALS

这项建议的长期目标是研究 使用体外测试系统检测空气中的污染物对肺细胞的影响。 提出了两个这样的系统：1)人的上、下呼吸道上皮 细胞培养；2)啮齿动物外周肺器官培养。这是我们的 假设拟议的测试系统将有助于确定 空气中污染物的毒性，无论是单独的还是混合的，都是 在城市环境和集中的职业环境中发现 与当今的曝光率有关。这些测试系统也将 用来研究沙门氏菌引起呼吸细胞损伤的机制 空气中的污染物。 具体目的是：1)暴露人的鼻腔和支气管上皮 细胞培养到低浓度的气体空气污染物，如臭氧 (O_3)和二氧化硫(SO_2)暴露出相同的两种上皮细胞 在独特设计的曝光室中进行细胞培养，将使 将细胞定量暴露在复杂的空气混合物中，如 在环境或环境中含有硫酸的气溶胶中发现的那些 和硫酸盐颗粒，以及在含有挥发性物质的职业环境中 在制造先进的有机化学品时产生的有机化学混合物 复合材料(ACM)；3)利用啮齿动物外周肺器官 培养物作为一种短期检测系统评价其毒性效应 制造ACM过程中产生的纤维和粉尘。 空气中的污染物将在相关浓度下进行测试 环境和职业暴露。浓度和时间 臭氧的持续时间范围为0.1、0.3或0.5ppm，持续1或3小时； 二氧化硫浓度为0.5、1或5ppm，持续30或60分钟。 含酸性硫酸盐的气溶胶颗粒是一种有毒成分 被污染的城市空气。硫酸盐气溶胶的酸度在引起 肺损伤将通过改变颗粒的酸度来确定。 铵与硫酸盐的比例将发生变化，从而使游离量 每个粒子沉积的酸量将从0到1000 attomoles/ 粒子以七个相等的对数步长。产生的有机蒸气 在此之前，将首先研究丙烯酰胺类物质的聚合 简单的双组分(苯酚-甲醛)模型体系，比 复杂的多组分混合物。加工过程中产生的粉尘和 ACM的分解将在肺器官培养中进行评估。 细胞损伤和组织损伤将通过一组检测来测量 系统地检测酶、代谢、功能和结构 反应，包括：1)51Cr释放，2)~3H-亮氨酸掺入；3) 细胞内ATP水平的变化；4)细胞内谷胱甘肽的变化 内容物；5)细胞增殖/细胞动力学；6)细胞间损失 缝隙连接通讯；7)上皮细胞形态。

The long-term objective of this proposal is to study the toxicity of airborne pollutants on lung cells with the use of in vitro test systems. Two such systems are proposed: 1) human upper and lower airway epithelial cell cultures; 2) rodent peripheral lung organ cultures. It is our hypothesis that the proposed test systems will be useful for determining the toxicity of airborne pollutants, individually and as mixtures, that are found in urban environments and in occupational settings at concentrations relevant to present-day exposures. These test systems will also be utilized to investigate mechanisms of respiratory cell injury caused by airborne pollutants. The specific aims are to: 1) expose human nasal and bronchial epithelial cell cultures to low concentrations of gaseous air pollutants such as ozone (O3) and sulfur dioxide (SO2) 2) expose the same two types of epithelial cell cultures within a uniquely designed exposure chamber that will allow quantitative exposure of the cells to complex airborne mixtures such as those found in ambient or environmental aerosols that contain sulfuric acid and sulfate particles and in occupational settings that contain volatile organic chemical mixtures generated during the manufacture of advanced composite materials (ACMs); 3) Utilize rodent peripheral lung organ cultures as a short-term assay system to evaluate the toxic effects of fibers and dusts generated during the manufacture of ACMs. The airborne pollutants will be tested at concentrations relevant to environmental and occupational exposures. The concentration and time duration ranges for O3 will be 0.1, 0.3, or 0.5 ppm for 1 or 3 hours; for SO2 the concentrations will be 0.5, 1 or 5 ppm for 30 or 60 minutes. Acidic sulfate-containing aerosol particles are a toxic component of polluted urban air. The role of acidity of sulfate aerosols in causing lung injury will be determined by varying the acidity of the particles. The ammonium to sulfate ratio will be varied such that the amount of free acid deposited per particle will be varied from 0 to 1000 attomoles per particle in seven equal logarithmic steps. The organic vapors generated prior to polymerization of ACMs will be studied first in a relatively simple two-component (phenol-formaldehyde) model system, than as more complex multi-component mixtures. Dusts generated during the machining and decomposition of ACMs will be evaluated in lung organ cultures. Cellular injury and tissue damage will be measured with a battery of assays to systemically examine enzymatic, metabolic, functional and structural responses, including: 1) 51Cr release, 2) 3H-leucine incorporation; 3) alteration of cellular ATP levels; 4) alteration of cellular glutathione content; 5) cell proliferation/cell kinetics; 6) loss of intercellular communication via gap junctions; 7) epithelial cell morphology.