Reaction and Diffusion of Nitric Oxide in Biological Systems

项目1.免疫系统细胞持续、高速率地产生一氧化氮(NO) 在慢性炎症期间，已经强烈地与各种形式的癌症的发展有关。 定量测定NO的病理生理水平对于理解内源性 NO合成与致癌。同样重要的是知道活性中间体的浓度 来源于NO，如二氧化氮(NO2)、亚硝酸酐(N2O)和过氧亚硝酸根(ONOO-)， 因为这些物种很可能是NO引起的细胞损伤的介体。不可能直接地 在大多数感兴趣的条件下测量任何这些化合物的浓度，但 需要信息来将细胞培养中的毒性水平和突变率与实际的 并将这些发现外推到体内的情况。还有一种“交付”的需求 控制细胞或生物溶液暴露于特定活性氮化合物的系统，因此 这种机械论假说可以在体外进行检验。为了满足这些需求，建议使用 结合递送系统开发、组织建模和动力学分析。使用气体的反应堆- 可渗透管将为NO2在生理水平上的输送提供一种新的方法，并将 改进控制接触N2O的方法。将利用微流控技术开发一种 ONOO-递送的新方法。将开发计算模型来预测NO浓度 在特定的组织中，包括发炎的结肠和黑色素瘤。NO合成、NO消耗和O2的速率 消耗将在代表这些组织的细胞系中进行测量，为 模特们。NO氧化途径及抗氧化剂与细胞反应的动力学分析 脂类将被用来预测定义的溶液中NO2、N2O3和相关自由基的浓度 细胞。这些预测将通过在体外测量选定生物标记物的产生速度来检验。

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.