The Nitric Oxide Producing Reactions of Hydroxyurea

羟基脲的一氧化氮生成反应

• 批准号: 6983407
• 负责人: S BRUCE King
• 金额: $ 27.31万
• 依托单位: WAKE FOREST UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-10 至 2007-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6983407
• 关键词: blood /lymphatic pharmacology; blood disorder chemotherapy; clinical research; enzyme activity; guanylate cyclase; hemoglobin; human subject; hydroxyurea; nitric oxide; pharmacokinetics; sickle cell anemia

DESCRIPTION (provided by applicant): Hydroxyurea represents a new treatment for sickle cell disease, a condition that affects 1 in 600 Americans of African descent. While the molecular mechanisms of how hydroxyurea beneficially affects sickle cell disease patients remain unknown, recent evidence indicates a role for nitric oxide (NO) in both the pathophysiology and treatment of sickle cell disease. The long-term goal of the proposed research is to thoroughly and clearly understand how the NO producing reactions of hydroxyurea contribute to the beneficial effects of hydroxyurea therapy. This goal is based upon the hypothesis that hydroxyurea-derived NO mediates the beneficial effects of hydroxyurea therapy in sickle cell disease. Product analysis, kinetic and spectroscopic studies will determine the mechanism of in vitro NO production from hydroxyurea, which should provide relevant information to the in vivo reaction. Similar studies applied to the incubation of hydroxyurea with various tissues and purified enzymes will reveal both the mechanism and site of in vivo NO formation from hydroxyurea. Specifically, these results will distinguish between hydrolytic and oxidative mechanisms of both in vitro and in vivo NO formation from hydroxyurea. In addition, the extent of the reaction of hydroxyurea-derived NO with the identified target proteins, soluble guanylate cyclase and cell-free hemoglobin, will be demonstrated by determining the extent of enzyme activation and the ultimate reaction products and kinetics of these reactions using spectroscopic methods and product analysis. These results will indicate the ability of hydroxyurea or hydroxyurea derived-NO to influence or react with these target proteins and provide evidence for a mechanism for the beneficial effects of hydroxyurea treatment. Unique hydroxyurea-based NO delivery systems and water-soluble nitroxyl donors will be prepared through chemical synthesis. The ability of these compounds to release NO will be determined using spectroscopic and cyclic voltammetric studies and these results will reveal the ability of these new systems to act as NO or nitroxyl donors. These new compounds will also be evaluated for their ability to stimulate soluble guanylate cyclase and react with cell free hemoglobin. Together, these results will provide important information regarding the mechanism of action of hydroxyurea that can be applied to the further development of superior sickle cell treatments.

描述（由申请人提供）：羟基脲代表了镰状细胞疾病的一种新疗法，这种疾病影响了600名非洲血统的美国人。虽然羟基脲如何有益地影响镰状细胞病患者的分子机制仍然未知，但最近的证据表明，一氧化氮（NO）在病理生理学和镰状细胞疾病的治疗中起作用。拟议研究的长期目标是彻底，清楚地了解羟基脲的无反应如何有助于羟基脲治疗的有益作用。该目标基于以下假设：羟基脲衍生的NO介导羟基脲治疗对镰状细胞病的有益作用。产品分析，动力学和光谱研究将确定羟基脲的体外NO生产机制，这些机制应为体内反应提供相关信息。类似的研究应用于羟基脲与各种组织和纯化酶的孵育，将揭示体内NO形成的机理和部位。具体而言，这些结果将区分体外和体内无羟基脲的水解和氧化机制。此外，将通过确定酶激活的程度以及使用光谱方法和产物分析的这些反应的最终反应产物和动力学来证明羟基脲衍生的NO与已鉴定的靶蛋白，可溶性鸟苷酸环化酶和无细胞血红蛋白的反应程度。这些结果将表明羟基脲或羟基脲衍生的不影响或与这些靶蛋白有反应的能力，并为羟基脲处理的有益作用提供了证据。独特的基于羟基脲的无输送系统和水溶性硝化供体将通过化学合成制备。这些化合物释放NO的能力将使用光谱和循环伏安法研究确定，这些结果将揭示这些新系统充当NO或硝基氧基供体的能力。这些新化合物还将评估它们刺激可溶性鸟苷酸环化酶并与无细胞血红蛋白反应的能力。总之，这些结果将提供有关羟基脲作用机理的重要信息，这些信息可用于进一步开发镰状细胞治疗的进一步发展。