The Effect of Angeli¿s salt on Acute Hemolysis in a Canine Model

安吉利盐对犬模型急性溶血的影响

• 批准号: 7593096
• 负责人: Charles Natanson
• 金额: $ 11.99万
• 依托单位: CLINICAL CENTER
• 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/7593096
• 关键词: Acute; Adverse effects; Angeli' s salt; Animals; Atherosclerosis; Binding; Biochemical; Blood Circulation; Blood flow; Canis familiaris; Cardiac; Cell membrane; Cells; Cessation of life; Characteristics; Chemicals; Consumption; Creatinine clearance measurement; Equilibrium; Erythrocytes; Gastrointestinal tract structure; Goals; Hand; Health; Heart; Hemoglobin; Hemolysis; High Blood Pressure; Human; Inflammation; Infusion procedures; Injury; Intravenous; Kidney; Laboratories; Measures; Methemoglobin; Modeling; Nitric Oxide; Nitrites; Organ; Oxyhemoglobin; Peripheral; Peripheral Resistance; Physiological; Plasma; Protocols documentation; Rate; Recycling; Renal function; Risk; System; Testing; Therapeutic; Toxic effect; Vascular Endothelium; Vasodilator Agents; Water; hemodynamics; indexing; inhaled nitric oxide; iron nitrosyl; nitrosyl hemoglobin; pressure; prevent; vasoconstriction

The primary goal of this study is to determine the therapeutic value of Angeli's salt (Na2N2O32-) in a canine model of acute intravascular hemolysis. Nitric oxide (NO) is a vasodilator which is constantly produced by the vascular endothelium. The amount of NO available in the circulation is, in part, regulated by the binding of NO to hemoglobin. Hemoglobin is normally contained within the red blood cell and reacts with nitric oxide at a relatively slow rate. However, the destruction of red blood cells within the circulation (intravascular hemolysis) causes the release of hemoglobin (cell-free hemoglobinh) from the red blood cell into the circulation. The cell-free hemoglobin released into the circulation during hemolysis binds to NO at a much faster rate than hemoglobin within the red blood cell. This binding of NO by cell-free hemoglobin disrupts the normal balance of NO available within the circulation resulting in vasoconstriction that decreases blood flow and leads to organ injury. Angeli's salt is known to react rapidly with hemoglobin to form, nitrosyl hemoglobin Fe(II)NO which does not bind NO. N2O3- (Angeli's Salt) NO2- + NO NO + Fe(II)-O2 (oxyhemoglobin in plasma) Fe(III) (methemoglobin) + Fe(III) + NO- Fe(II)-NO (iron-nitrosyl-hemoglobin) If the Angeli's salt can prevent the cell-free hemoglobin from binding NO, it may prevent the vasoconstriction and resulting organ injury that occurs during hemolysis. This study will test the ability of Angeli's salt to prevent cell-free hemoglobin binding of NO during hemolysis using the canine model of intravascular hemolysis that we successfully developed and used in two previous protocols. Our model uses a free water infusion to create intravascular hemolysis which mimics the physiologic and biochemical characteristics of acute intravascular hemolysis in the human. This model disrupts the red cell membrane within the circulation leading to the release of hemoglobin into circulation of the animal. In our model, acute intravascular hemolysis leads to changes in hemodynamics and organ function, i.e., increases in mean arterial pressure and systemic vascular resistance and decreases in heart and kidney function as measured by cardiac index and creatinine clearance respectively. Previous studies in our laboratory showed that elevated levels of cell-free hemoglobin consume NO, and therapy with inhaled nitric oxide or intravenous nitrite can limit the deleterious effects of intravascular hemolysis. Despite the demonstrated benefits, these two therapies have limitations. Inhaled nitric oxide is expensive, requires a specialized delivery system and is not readily available. Intravenous nitrite, although inexpensive and easy to administer, reacts slowly with cell free hemoglobin. Both therapies produce methemoglobin which: (1) promotes inflammation, (2) is associated with atherosclerosis and (3) can potentially undergo reduction and be recycled to free hemoglobin. Angeli's salt, on the other hand, has been shown to rapidly react with hemoglobin to produce nitrosyl hemoglobin. Unlike methemoglobin, (the product of nitrite or NO reacting with hemoglobin), nitrosyl hemoglobin is relatively stable and with no known toxicities. Angeli's salt also has the advantage of being inexpensive and can be administered intravenously. Thus, the chemical profile of Angeli's salt suggests that it should irreversibly react with cell free hemoglobin thereby preventing the consumption of NO, possibly reverse the adverse effects of intravascular hemolysis and have fewer side effects than either nitric oxide or nitrite therapy.

本研究的主要目的是确定Angeli盐（Na 2N 2 O32-）在犬急性血管内溶血模型中的治疗价值。一氧化氮（NO）是一种血管扩张剂，其由血管内皮持续产生。循环中可用的NO的量部分地由NO与血红蛋白的结合来调节。血红蛋白通常包含在红细胞中，并以相对缓慢的速度与一氧化氮反应。然而，循环中红细胞的破坏（血管内溶血）导致血红蛋白（无细胞血红蛋白）从红细胞释放到循环中。 在溶血过程中释放到循环中的无细胞血红蛋白以比红细胞内的血红蛋白快得多的速率与NO结合。这种NO与无细胞血红蛋白的结合破坏了循环中可用的NO的正常平衡，导致血管收缩，从而减少血流量并导致器官损伤。 已知Angeli的盐与血红蛋白快速反应以形成不结合NO的亚硝基血红蛋白Fe（II）NO。 N2O3-（Angeli's Salt）NO2- + NO NO + Fe（II）-O2（血浆中的氧合血红蛋白）Fe（III）（高铁血红蛋白）+ Fe（III）+ NO- Fe（II）-NO（铁-亚硝基-血红蛋白） 如果Angeli的盐可以防止无细胞血红蛋白结合NO，它可以防止血管收缩和溶血过程中发生的器官损伤。本研究将使用我们成功开发并用于先前两个方案的血管内溶血犬模型来测试Angeli盐在溶血期间防止NO的无细胞血红蛋白结合的能力。我们的模型使用自由水输注来产生血管内溶血，其模拟人类急性血管内溶血的生理和生化特征。 该模型破坏循环中的红细胞膜，导致血红蛋白释放到动物的循环中。在我们的模型中，急性血管内溶血导致血液动力学和器官功能的变化，即，平均动脉压和全身血管阻力增加，以及分别通过心脏指数和肌酐清除率测量的心脏和肾功能降低。 我们实验室以前的研究表明，无细胞血红蛋白水平升高会消耗NO，吸入一氧化氮或静脉注射亚硝酸盐治疗可以限制血管内溶血的有害影响。 尽管这两种疗法都有好处，但都有局限性。 吸入一氧化氮是昂贵的，需要专门的输送系统，并且不容易获得。 静脉注射亚硝酸盐，虽然便宜，易于管理，反应缓慢，与细胞游离血红蛋白。 这两种疗法都产生高铁血红蛋白，其：（1）促进炎症，（2）与动脉粥样硬化有关，（3）可以潜在地进行还原并再循环为游离血红蛋白。 另一方面，Angeli的盐已被证明能迅速与血红蛋白反应生成亚硝基血红蛋白。 与高铁血红蛋白（亚硝酸盐或NO与血红蛋白反应的产物）不同，亚硝基血红蛋白相对稳定，没有已知的毒性。 Angeli的盐也有便宜的优点，可以静脉注射。 因此，Angeli盐的化学特性表明，它应该与无细胞血红蛋白发生不可逆的反应，从而防止NO的消耗，可能逆转血管内溶血的不良作用，并且比一氧化氮或亚硝酸盐疗法具有更少的副作用。