Reaction and Diffusion of Nitric Oxide in Biological Systems

项目1。免疫系统细胞持续高速率产生一氧化氮（NO）， 在慢性炎症期间，与各种形式的癌症的发展密切相关。 量化NO的病理生理水平对于了解内源性与NO的关系至关重要。 NO合成与致癌作用同样重要的是知道反应中间体的浓度 源自NO，如二氧化氮（NO2）、亚硝酸酐（N2 O3）和过氧亚硝酸根（ONOO-）， 因为这些物质可能是NO引起的细胞损伤的介质。 在大多数感兴趣的条件下测量任何这些化合物的浓度，然而， 需要信息来将细胞培养物中的毒性水平和突变率与实际水平相关联， 暴露，并将这些发现外推到体内的情况。还需要“交付 系统”来控制细胞或生物溶液暴露于特定的活性氮化合物， 机械假说可以在体外测试。建议使用一个 递送系统开发、组织建模和动力学分析的组合。使用气体的反应器- 可渗透管将用于提供一种新的方法，在生理水平上输送NO2， 控制暴露于N2 O3改进方法。微流体技术将被用来开发一种 用于递送ONOO-的新方法。将开发计算模型来预测NO浓度 包括发炎的结肠和黑素瘤NO合成、NO消耗和O2的速率 将在代表这些组织的细胞系中测量消耗量，为 模特们NO氧化途径和涉及抗氧化剂和细胞反应的动力学分析 脂质将被用来预测浓度的NO2，N2 O3，和相关的自由基在规定的解决方案， 细胞这些预测将通过测量体外选定生物标志物的产生速率进行测试。

Project 1. Sustained, high rates of production of nitric oxide (NO) by cells of the immune system, as occurs during chronic inflammation, has been strongly implicated in the development of various forms of cancer. Quantifying pathophysiological levels of NO is crucial for understanding the relationship between endogenous NO synthesis and carcinogenesis. Equally important is knowing the concentrations of reactive intermediates derived from NO, such as nitrogen dioxide (NO2), nitrous anhydride (N2O3), and peroxynitrite (ONOO-), because these species are likely mediators of damage to cells arising from NO. It is not feasible to directly measure the concentrations of any of these compounds under most conditions of interest, yet such information is needed to correlate levels of toxicity and rates of mutation in cell cultures with actual levels of exposure, and to extrapolate those findings to situations in the body. There is a need also for "delivery systems" to control the exposure of cells or biological solutions to specific reactive nitrogen compounds, so that mechanistic hypotheses can be tested in vitro. It is proposed to address these needs using a combination of delivery system development, tissue modeling, and kinetic analysis. Reactors employing gas- permeable tubing will be used to provide a new method for NO2 delivery at physiological levels and to improve methods for controlled exposure to N2O3. Microfluidics technology will be exploited to develop a novel approach for delivery of ONOO-. Computational models will be developed to predict NO concentrations in specific tissues, including inflamed colon and melanoma. Rates of NO synthesis, NO consumption, and O2 consumption will be measured in cell lines that are representative of these tissues, providing key inputs for the models. A kinetic analysis of NO oxidation pathways and of reactions involving antioxidants and cellular lipids will be used to predict concentrations of NO2, N2O3, and related radicals in defined solutions and in cells. These predictions will be tested by measuring rates of production of selected biomarkers in vitro.