IN VITRO TOXICITY OF AIRBORNE POLLUTANTS AND CHEMICALS

这项建议的长远目标是研究 空气中的污染物对肺细胞的体外测试系统的使用。 提出了两个这样的系统：1）人上气道上皮和下气道上皮 细胞培养; 2）啮齿动物外周肺器官培养。 是我们 假设拟议的测试系统将有助于确定 空气中污染物的毒性，单独和混合物， 在城市环境和职业环境中发现的浓度 与当前的暴露有关。 这些测试系统也将 用于研究呼吸细胞损伤的机制， 空气污染物。 具体目的是：1）暴露人鼻和支气管上皮细胞 细胞培养物暴露于低浓度的气态空气污染物如臭氧 (O3)和二氧化硫（SO2）2）暴露相同的两种类型的上皮 在一个独特设计的暴露室中进行细胞培养， 细胞定量暴露于复杂的空气传播混合物， 那些存在于含有硫酸的环境气溶胶中的物质 和硫酸盐颗粒，在职业环境中， 有机化学混合物生产过程中产生的先进的 复合材料（ACM）; 3）利用啮齿动物外周肺器官 培养物作为短期试验系统，以评价 纤维和粉尘在ACM制造过程中产生。 空气中的污染物将在以下浓度下进行测试： 环境和职业暴露。 浓度和时间 O3的持续时间范围为0.1、0.3或0.5 ppm，持续1或3小时;对于 SO2浓度为0.5、1或5 ppm，持续30或60分钟。 酸性含硫酸盐气溶胶颗粒是一种有毒成分， 城市空气污染。 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。 铵与硫酸盐的比率将变化，使得游离的硫酸盐的量增加。 每个颗粒沉积的酸将从0到1000阿托摩尔变化。 粒子在七个相等的对数步骤。 产生的有机蒸汽 在聚合ACM之前，将首先在相对 简单的双组分（苯酚-甲醛）模型体系， 复杂的多组分混合物。 加工过程中产生的粉尘， 将在肺器官培养物中评价ACM的分解。 细胞损伤和组织损伤将通过一系列试验进行测量 系统地检查酶，代谢，功能和结构 反应，包括：1）51 Cr释放，2）3 H-亮氨酸掺入; 3） 细胞ATP水平的改变; 4）细胞谷胱甘肽的改变 含量; 5）细胞增殖/细胞动力学; 6）细胞间 通过缝隙连接进行通讯; 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.