HYPOXIC PULMONARY VASOCANSTRICTION AND RED BLOOD CELLS

描述 (摘自申请者的摘要)有证据表明，一氧化氮(NO) 在红细胞(RBC)介导的低氧调节中起重要作用 肺血管收缩(HPV)。NO可能直接参与了这件事 调节，或可能通过其与血红蛋白的结合而间接起作用 (Hb)形成S亚硝基血红蛋白(SNO-Hb)。此外，嘌呤类物质 腺苷和三磷酸腺苷(ATP)可能在调节 红细胞测定肺血管张力。红细胞和人乳头状瘤病毒之间的相互作用是 临床上相关，因为贫血和贫血共同存在 危重病人的肺部疾病。这样做的具体目的是 项目有：1.确定NO生产操纵效果 代谢或外源性应用NO对肺血管张力的影响 在常氧和低氧期间。2.区分以下角色： 完整的RBC及其成分Hb单独处于无代谢和调节状态 并确定SNO-HB在调节HPV基因表达中的作用。 肺血管张力。3.测量肺动脉内皮细胞 在封闭系统中产生NO，并确定低氧的影响 红细胞对内皮细胞产生NO的影响。4.阐明红细胞在以下方面的作用 阻断肺血管摄取的嘌呤能调节肺血管张力 腺苷通过红细胞、通过阻断嘌呤受体和通过测定嘌呤能 常氧和低氧条件下的中介物产生。5.确定 嘌呤是否影响肺动脉内皮细胞释放NO 在一个封闭的系统中。这些目标将使用独立的、 重复灌流建立兔肺组织HPV定量模型 低氧气体挑战不同的血细胞数，并与培养的 肺动脉内皮细胞模型。调解人将使用以下方法进行检测 化学发光法测定人体内过期的NO及其代谢物 灌流液、光解化学发光法测定SNO-Hb和High 加压高效液相色谱法测定灌流液中的嘌呤。

DESCRIPTION (Adapted from applicants' abstract) There is evidence that nitric oxide (NO) is important in red blood cell (RBC)-mediated modulation of hypoxic pulmonary vasoconstriction (HPV). NO may be involved directly in this modulation, or may act indirectly through its combination with hemoglobin (Hb) to form S-nitrosohemoglobin (SNO-Hb). In addition, the purines adenosine and adenosine triphosphate (ATP) may play a role in modulation of pulmonary vascular tone by RBCs. The interactions between RBCs and HPV are clinically relevant because of the common coexistence of anemia and pulmonary disease in critically ill patients. The specific aims of this project are: 1. To determine the effects of manipulation of NO production and metabolism or exogenously administered NO on pulmonary vascular tone during normoxia and hypoxia. 2. To distinguish between the roles played by the intact RBC and its constituent Hb alone in NO metabolism and modulation of HPV, and to determine the potential role of SNO-Hb in modulation of pulmonary vascular tone. 3. To measure pulmonary artery endothelial cell production of NO in a closed system, and to determine the effects of hypoxia and RBCs on endothelial NO production. 4. To elucidate the role of RBCs in purinergic modulation of pulmonary vascular tone by blocking uptake of adenosine by RBCs, by blocking purine receptors, and by assaying purinergic mediator production under normoxic and hypoxic conditions. 5. To determine whether purines affect release of NO by pulmonary artery endothelial cells in a closed system. These aims will be investigated using an isolated, perfused rabbit lung model with quantitiation of HPV done during repeated hypoxic gas challenges at different hematocrits, and with a cultured pulmonary artery endothelial cell model. Mediators will be assayed using chemiluminescence for measurement of expired NO and NO metabolites in perfusate, photolysis chemiluminescence for measurement of SNO-Hb, and high pressure liquid chromatography for measurement of purines in perfusate.