Red Blood Cell Function in Nitric Oxide Biotransport

红细胞在一氧化氮生物转运中的功能

• 批准号: 7456844
• 负责人: MAHENDRA KAVDIA
• 金额: $ 20.78万
• 依托单位: UNIVERSITY OF ARKANSAS AT FAYETTEVILLE
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-06-01 至 2011-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7456844
• 关键词: Area; Binding; Bioavailable; Biochemical; Biological Availability; Bioreactors; Blood Substitutes; Blood Vessels; Cell Communication; Cell membrane; Cell physiology; Chronic; Consumption; Data; Development; Electrodes; Endothelium; Erythrocytes; Evaluation; Experimental Models; Functional disorder; Goals; Hemoglobin; Hemolysis; Immune response; Knowledge; Lead; Measures; Metabolism; Methods; Microcirculation; Nitrates; Nitric Oxide; Nitrites; Oxygen; Physiological; Physiology; Platelet Aggregation Inhibition; Play; Production; Public Health; Pulmonary Hypertension; Purpose; Rate; Reaction; Regulation; Research; Research Personnel; Role; Septic Shock; Sickle Cell Anemia; Simulate; Site; Smooth Muscle; Soluble Guanylate Cyclase; Solutions; Study models; Testing; Therapeutic; aqueous; base; design; glycosylated-nitric oxide complex hemoglobin A; hemodynamics; in vivo; neurotransmission; nitrate; novel; Area; Binding; Bioavailable; Biochemical; Biological Availability; Bioreactors; Blood Substitutes; Blood Vessels; Cell Communication; Cell membrane; Cell physiology; Chronic; Consumption; Data; Development; Electrodes; Endothelium; Erythrocytes; Evaluation; Experimental Models; Functional disorder; Goals; Hemoglobin; Hemolysis; Immune response; Knowledge; Lead; Measures; Metabolism; Methods; Microcirculation; Nitrates; Nitric Oxide; Nitrites; Oxygen; Physiological; Physiology; Platelet Aggregation Inhibition; Play; Production; Public Health; Pulmonary Hypertension; Purpose; Rate; Reaction; Regulation; Research; Research Personnel; Role; Septic Shock; Sickle Cell Anemia; Simulate; Site; Smooth Muscle; Soluble Guanylate Cyclase; Solutions; Study models; Testing; Therapeutic; aqueous; base; design; glycosylated-nitric oxide complex hemoglobin A; hemodynamics; in vivo; neurotransmission; nitrate; novel

DESCRIPTION (provided by applicant): Our long-term goal is to quantify nitric oxide (NO) transport in the microcirculation in physiology and pathophysiology. In vascular wall, endothelium-derived nitric oxide reaches smooth muscle where it can activate soluble guanylate cyclase (sGC) and modulate vascular tone. The level of bioavailable NO are maintained by its production and consumption in the microcirculation. Despite intense research on the transport of NO from the production site (endothelium) to the target site (smooth muscle), question remains on whether and how significant amount of endothelium-derived NO reaches smooth muscle in the presence of efficient NO scavenger red blood cells (RBCs) in vascular lumen. The proposed research will provide functional relationship between hemodynamic and biochemical parameters in NO and RBC interaction. The Specific Aims for the proposed research are 1) to determine the role of oxygenation on NO interaction with RBC and 2) to quantify the differences in NO end-products formation from NO interaction with free Hb and RBC Hb. Based on the preliminary data, the hypotheses we will test are that (a) NO interaction with oxygenated RBCs will result in higher nitrite formation rate as compared to nitrite formation rate of NO interaction with deoxygenated RBCs, (b) oxygenated RBCs will have higher total NO concentration as compared to total NO concentration of deoxygenated RBCs, and (c) hemoglobin bound in the RBC membrane (RBC-hemoglobin) will results in higher total NO concentration and thus will have higher NO bioavailability as compared to that of free hemoglobin solution or RBC solution containing small amount of free Hb. For testing these hypotheses, we will use a novel bioreactor that simulates in vivo interactions of NO and RBCs. We will compare interaction products of NO with oxygenated- and deoxygenated- RBCs, presence of free hemoglobin with RBCs, and free hemoglobin. We will measure the reaction products of NO including intermediate products (s-nitrosohemoglobin & nitrosyl-Hb) and end-products (nitrite & nitrate) using chemiluminescence method. We will measure the gaseous and aqueous NO concentration using an NO electrode. We will additionally use UV/Vis spectrophotometric spectrum to quantify these concentration. By designing a new experimental model for studying biochemical interactions of NO and RBCs, we will advance the knowledge of biomedical researchers on these molecular interactions. This may lead to evaluation of therapeutics in areas as diverse as sickle cell anemia, pulmonary hypertension, septic shock, and blood substitutes. PUBLIC HEALTH RELEVANCE: Nitric oxide (NO) plays important roles in numerous physiological functions including regulation of vascular tone, neurotransmission, immune response and inhibition of platelet aggregation. The proposed research will significantly advance our fundamental understanding of NO metabolism in the microcirculation and provide biomedical researchers a new experimental model for studying biochemical interactions of NO and RBCs. The proposed research will also quantify the effect of free Hb on the NO metabolism. This knowledge is critical to the development of hemoglobin based oxygen carrier and the understanding the effects of chronic hemolysis in sickle cell disease and pulmonary hypertension.

描述（由申请人提供）：我们的长期目标是在生理学和病理生理学的微循环中量化一氧化氮（NO）的转运。在血管壁中，内皮衍生的一氧化氮达到平滑肌，它可以激活可溶性鸟苷酸环化酶（SGC）并调节血管张力。生物利用NO的水平通过其在微循环中的生产和消耗来维持。尽管对NO从生产地点（内皮）转移到目标部位（平滑肌）的深入研究，但在有效的血管腔内有效的无寻宝红血细胞（RBC）的情况下，问题仍然存在问题，以及在有效的无寻宝红细胞（RBC）的情况下是否有大量的内皮衍生的NO达到平滑肌。拟议的研究将在NO和RBC相互作用中提供血液动力学和生化参数之间的功能关系。拟议研究的具体目的是1）确定氧合在与RBC相互作用的相互作用和2）之间的作用，以量化无终产物形成的差异，而无需与游离HB和RBC HB相互作用。基于初步数据，我们将测试的假设是（a）与含氧的RBC相比，与非相互作用的硝酸盐形成速率相比，与去氧型RBC相比，（b）含氧RBC的含量较高的浓度与DEDOX相比，（b）与含氧的RBC相比，将导致较高的亚硝酸盐的形成速率，与DEOX的总浓度相比，RBC的总浓度较高（C） RBC膜（RBC-Hemoglobin）将导致较高的总无浓度，因此与含有少量游离HB的游离血红蛋白溶液或RBC溶液相比，将具有更高的无生物利用度。为了测试这些假设，我们将使用一种新型的生物反应器，该生物反应器模拟NO和RBC的体内相互作用。我们将将NO的相互作用产物与氧化和脱氧的RBC，具有RBC的游离血红蛋白和游离血红蛋白进行比较。我们将使用化学发光方法测量NO包括中间产物（S-硝基血红蛋白和硝基-HB）和终产物（亚硝酸盐和硝酸盐）的反应产物。我们将使用NO电极测量气体和水性NO浓度。我们还将使用UV/VIS分光光度计光谱来量化这些浓度。通过设计一种用于研究NO和RBC的生化相互作用的新实验模型，我们将促进生物医学研究人员对这些分子相互作用的了解。这可能会导致评估如镰状细胞贫血，肺动脉震动和血液替代品等多样性的治疗剂。公共卫生相关性：一氧化氮（NO）在许多生理功能中起着重要作用，包括调节血管张力，神经传递，免疫反应和血小板聚集的抑制。拟议的研究将显着提高我们对微循环中NO代谢的基本理解，并为生物医学研究人员提供一种研究NO和RBC的生化相互作用的新实验模型。拟议的研究还将量化游离HB对NO代谢的影响。这种知识对于基于血红蛋白的氧载体的发展至关重要，以及理解慢性溶血对镰状细胞疾病和肺动脉高压的影响。