METABOLIC ACTIVATION OF AIR TOXICS IN ASTHMATIC MONKEYS

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 萘是一种挥发性碳氢化合物，在啮齿类动物急性暴露后会引起剂量、种类和细胞类型依赖性的细胞毒性，在终生暴露后会引起增殖/肿瘤。毒性依赖于代谢激活，而反应性代谢物蛋白结合与组织和部位敏感性相关。人类接触萘是一种普遍现象，而且是通过各种与燃烧有关的来源发生的，但缺乏人类接触对健康影响的流行病学证据。在大鼠和猕猴的鼻黏膜上皮细胞中，研究了被认为对萘的毒性至关重要的过程的比较研究。 从鼻上皮和14C-萘孵育中回收加合物蛋白，用2D凝胶电泳法分离并成像，以配准放射性蛋白。非放射性凝胶上的银染蛋白通过肽质量图谱进行鉴定。恒河猴筛上鼻甲孵育的反应性代谢物结合水平与靶组织孵育的水平相似，包括大鼠隔/嗅区和小鼠解剖的呼吸道孵育。从大鼠嗅觉上皮蛋白的2D凝胶分离中鉴定出41个加合物斑点；其中23个是非冗余的。在猴子身上，通过质谱仪鉴定了19个斑点，产生了3个非冗余的鉴定。结构蛋白(肌动蛋白/微管蛋白)在两个物种中都是显著的靶标。这些研究确定了潜在的靶蛋白，它们可能作为与毒性密切相关的标记。先前报道的小鼠和猴子解剖的呼吸道中的萘代谢率与水溶性代谢物的比率之间的巨大差异，并没有反映在鼻子中形成共价加合物的类似差异中。这引起了人们的担忧，即下游的代谢/生化事件在大鼠和猕猴之间非常相似，大鼠是已知的萘毒性和致瘤性的目标，猕猴是与人类相似的物种。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Naphthalene is a volatile hydrocarbon which causes dose, species and cell type dependent cytotoxicity after acute exposure and hyperplasia/neoplasia after lifetime exposures in rodents. Toxicity depends upon metabolic activation, and reactive metabolite protein binding correlates with tissue and site susceptibility. Human exposure to naphthalene is universal and occurs from a variety of combustion-related sources but epidemiologic evidence for health effects of human exposure are lacking. Comparative studies examining processes thought to be essential to the toxicity of naphthalene have been examined in nasal epithelium of rats and Rhesus macaques. Adducted proteins recovered from incubations of nasal epithelium and 14C-naphthalene were separated by 2D gel electrophoresis and imaged to register radioactive proteins. Proteins visualized by silver staining on complimentary nonradioactive gels were identified by peptide mass mapping. The levels of reactive metabolite binding in incubations of Rhesus ethmo- and maxilloturbinate are similar to those in incubations of target tissues including rat septal/olfactory regions and murine dissected airway incubations. Forty one adducted spots were identified from 2D gel separations of rat olfactory epithelial proteins; 23 of these were nonredundant. In monkeys, 19 spots were identified by mass spectrometry yielding 3 nonredundant identifications. Structural proteins (actin/tubulin) were prominent targets in both species. These studies identified potential target proteins which may serve as markers closely associated with toxicity. The large differences previously reported between the rates of naphthalene metabolism to water soluble metabolites in dissected airways from mice and monkeys are not reflected in similar differences in covalent adduct formation in the nose. This raises concerns that downstream metabolic/biochemical events are very similar between the rat, a known target for naphthalene toxicity and tumorigenicity, and the Rhesus macaque, a species similar to the human.