Clinical Applications of Nitrite

亚硝酸盐的临床应用

• 批准号: 8553407
• 负责人: Alan Schechter
• 金额: $ 51.88万
• 依托单位: NATIONAL INSTITUTE OF DIABETES AND DIGESTIVE AND KIDNEY DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8553407
• 关键词: Affect; American; Animal Model; Animals; Ascorbic Acid; Bacteria; Biological Assay; Biological Preservation; Blood; Blood Banks; Blood Cells; Blood Circulation; Blood Platelets; Blood Vessels; Blood flow; Brain; Breathing; Cardiac; Cell model; Cells; Cerebrovascular Circulation; Clinical; Clinical Protocols; Collaborations; Consumption; Coupling; Detergents; Diet; Disease; Drug Kinetics; Endothelial Cells; Enzymes; Erythrocytes; Erythropoietin; Excision; Exhalation; FDA approved; Ferricyanides; Food; Gene Expression; Goals; Grant; Half-Life; Hemoglobin; Hemolysis; Hour; Human; Hypoxia; Image; Individual; Infusion procedures; Institutional Review Boards; Ions; Laboratory Study; Lead; Lesion; Leukocytes; Lung diseases; Mammalian Cell; Mammals; Measures; Meat Products; Medicine; Methods; Microcirculation; Molecular Profiling; National Heart, Lung, and Blood Institute; Neurons; Nitrates; Nitric Oxide; Nitric Oxide Donors; Nitric Oxide Synthase; Nitrites; Nutritional; Oral cavity; Organism; Pain; Pain Origin; Patients; Physiological; Plants; Plastics; Portugal; Procedures; Process; Production; Property; Publishing; Reaction; Red Cross; Relative (related person); Rodent; Role; Severities; Sickle Cell; Sickle Cell Anemia; Solutions; Stress; Sulfhydryl Reagents; Supplementation; System; Temperature; Testing; Therapeutic; Toxicology; Transfusion; United States National Institutes of Health; Venous; Whole Blood; Work; ascorbate; base; bench to bedside; brachial artery; cell type; clinical application; diaries; extracellular; falls; ferricyanide; improved; inhaled nitric oxide; inhibitor/antagonist; macrophage; microbiome; mouse model; neuronal cell body; nitrosyl hemoglobin; oxidation; protective effect; receptor; research study; sickling; volunteer

Among the studies recently completed to characterize the role of nitrite as a possible therapeutic option in situations where there is a relative deficiency of nitrite bioactivity are our studies with a mouse model of sickle cell anemia that we have been analyzing for a number of years and our studies in collaboration with the Department of Transfusion Medicine of the NIH Clinical Center on changes in nitrite levels in stored blood. The results with the animal model have been published and will not be summarized further here. In previous studies with human red cells, we found that upon removal of these cells from the body, levels of intracellular nitrite fell rapidly with a half life of less than an hour; we devised a preservation solution using ferricyanide, a thiol reagent and a detergent and could permanetly stabilize these levels. With these methods we found that human red cells normally have a nitrite concentration of about 300 nanomolar, while whole blood levels are about one-half of this, suggesting that most blood nitrite is in erythrocytes. Using these methods we have systematically measured nitrite and nitrate levels in stored whole blood, and red cells both with and without leukoreduction, to see the effects of other components of the blood on nitrite production and or consumption. We find that nitrate levels remain very constant at about 30 micromolar but, to our surprise, we find that the initial rapid fall in nitrite levels tapers and for as long as 42 days significant nitrite levels (about 50 nanomolar) remain in the stored red cells. The levels are comparable in all three methods of storage. We are now conducting studies to establish the mechanism of partial nitrite preservation in stored blood and to see if nitrite supplementation improves the properties of these red cells. In addition, several other studies with long term goals of defining clinical uses of nitrite are being done or being planned at present. We find no evidence of a role of S-nitrosated hemoglobin in the proposed "storage lesion" affecting red blood cells used for transfusion. In collaboration with the NIH Imaging Center we have been examining the effects of changes in nitric oxide levels on blood flow and function in the brains of rodents. We have worked out conditions so that there is no change in systemic or cerebral blood flow with the administration of a nNOS inhibitor but find that their are significant changes in brain function, which is restored with certain nitric oxide donors, including nitrite ions. We are now testing the pharmacological effects of nitrite on brain function and find that nitrite can restore neurovascular coupling. Further it appears that the high levels of intracellular and extracellular ascorbate in the brain may contribute to the reduction of nitrite to generate NO and we are now testing this hypothesis with rodents that can not synthesize ascorbate themselves and thus we can control ascorbate levels by exogenous administration. We have started a project with NHLBI, NINR, and the DTM of the Clinical Center to study the role of NO depletion in causing painful crises in sickle cell anemia patients. We are measuring levels of hemolysis and evidence of NO destruction by cell-free hemoglobin to see if these parameters correlated with manifestations of the disease. We have recently received an NIH Bench/Bedside grant for this work and have developed two clinical protocols which have been approved by the appropriate IRB to administer pain diaries to sickle cell patients, to measure nitrite, nitrate and exhaled NO levels in these patients as well as gene expression profiles in their leukocytes to see if we can identify markers of pain severity. In our project in collaboration with the American Red Cross to study the role of nitrite ions in the viability and storage of human platelets we have found that there is a small change in nitrate levels during five days of room temperature storage and that nitrite levels decrease but only about to 50% levels and then remain stable; some of this appears to be leached from the plastic of the storage bags. We are studying the significance of this finding and the need for nitrite ions in the retention of platelet viability during storage. We have also completed studies of the protective effects of erythropoietin on cardiac and other cells in culture and have shown that this agent protects against hypoxia and other stresses by increasing NO production (as measured by nitrite), especially in endothelial cells, as well as the erythopoeitin receptor itself. Lastly, as part of this work we have prepared and published two reviews of the state of nitrate and nitrite in the diet as having potential nutritional benefits in protecting against cardiac and other diseases. Although it is too early to know the long effects of such supplements, there is reason to be optimistic that they may be of benefit and the concerns that limited their use in the past were not significant.

在最近完成的研究中，我们的研究是我们的研究，即在存在相对缺乏亚硝酸盐生物活性的情况下，这是一种可能的治疗选择，这是我们的研究是通过镰状细胞贫血的小鼠模型的研究，我们已经分析了多年的研究，并且我们与NIH临床中心的合作中的研究在nihih clunical clunnical Clunnical Chernation of Nih clunchical Charternical carlance niter nitrite consect interrite sceptertical internord sceptorce carthored consected nitrore sceptorce consected。 动物模型的结果已经发布，在这里不会进一步总结。 在先前对人类红细胞的研究中，我们发现在从体内移除这些细胞后，细胞内亚硝酸盐的水平迅速下降，半寿命不到一个小时。我们使用铁氰化物，硫醇试剂和一种洗涤剂设计了一种保存溶液，并可以永久稳定这些水平。 通过这些方法，我们发现人红细胞通常的亚硝酸盐浓度约为300纳摩尔，而全血液水平约为其中的一半，这表明大多数血液亚硝酸盐都在红细胞中。 使用这些方法，我们已经系统地测量了储存的全血的亚硝酸盐和硝酸盐水平，红细胞都与 并且没有白细胞生成，可以看到血液的其他成分对亚硝酸盐产生和 /或消费的影响。 我们发现，硝酸盐水平在大约30个微摩尔时保持非常恒定，但令我们惊讶的是，我们发现亚硝酸盐水平锥度的最初迅速下降，长达42天的一亚硝酸盐水平（约50纳摩尔）仍保留在储存的红细胞中。 在所有三种存储方法中，这些级别均相当。 现在，我们正在进行研究，以建立储存血液中局部亚硝酸盐保存的机理，并查看亚硝酸盐补充是否可以改善这些红细胞的特性。 此外，目前正在进行或计划的其他一些具有定义亚硝酸盐临床用途的长期目标的研究。我们没有发现S-硝化血红蛋白在影响用于输血的红细胞的拟议“储存病变”中的作用的证据。 与NIH成像中心合作，我们一直在研究一氧化氮水平变化对啮齿动物大脑中血流和功能的影响。我们已经解决了条件，因此使用NNOS抑制剂的给药，系统性或脑血流不会发生变化，但发现它们是脑功能的显着变化，这与某些一氧化氮供体（包括亚硝酸盐离子）恢复。 现在，我们正在测试亚硝酸盐对脑功能的药理作用，并发现亚硝酸盐可以恢复神经血管耦合。此外，看来大脑中高水平的细胞内和细胞外抗坏血酸可能有助于减少亚硝酸盐的生成NO，现在我们正在用无法综合抗坏血酸的啮齿动物来测试这一假设，因此我们可以通过外源给药来控制抗坏血酸水平。 我们已经与NHLBI，NINR和临床中心的DTM一起开始了一个项目，以研究无耗尽在引起镰状细胞贫血患者疼痛危机方面的作用。 我们正在测量溶血水平和无细胞血红蛋白破坏的证据，以查看这些参数是否与疾病的表现相关。我们最近收到了NIH的长凳/床边赠款 对于这项工作，并且已经开发了两种临床方案，这些方案已得到适当的IRB批准的，以对镰状细胞患者进行疼痛日记，以测量这些患者的硝酸盐，硝酸盐和呼气，以及在其白细胞中的基因表达谱，以查看我们是否可以识别出疼痛严重程度的标记。 在我们的项目中与美国红十字会合作学习 亚硝酸盐离子在人血小板的生存能力和储存中的作用，我们发现在室温储存的五天内，硝酸盐水平的变化很小，亚硝酸盐水平降低，但仅降低到50％，然后保持稳定。其中一些似乎是从存储袋的塑料中浸出的。 我们正在研究这一发现的重要性以及对储存过程中血小板生存能力保留血小板活力的需求。 我们还完成了促红细胞生成素对培养中心脏和其他细胞的保护作用的研究，并表明该药物通过增加无生产（如亚硝酸盐衡量），尤其是在内皮细胞中以及在内皮细胞中，尤其是在内皮细胞中，可以预防缺氧和其他应力。 红斑蛋白受体本身。 最后，作为这项工作的一部分，我们准备了两项关于饮食中硝酸盐和亚硝酸盐状态的评论，因为它在保护心脏和其他疾病方面具有潜在的营养益处。尽管现在知道这种补充剂的长期影响还为时过早，但有理由乐观地认为它们可能有益，而过去限制其使用情况的担忧并不重要。