Nitric Oxide Interaction with Red Blood Cells

描述（由申请人提供）：一氧化氮（NO）通过其合成和失活之间的平衡实现其生物学功能。NO的生物合成受到高度调控，并且有很好的记录，而其失活则知之甚少。NO失活的主要途径包括与氧合血红蛋白[HbFe（II）O2]和各种自由基的反应。传统观点认为，由于NO被认为自由且快速地扩散穿过红细胞（RBC）膜，因此HbFe（II）O2对NO的灭活不受调节。最近的研究表明，NO进入红细胞的转运是由膜骨架蛋白控制的。红细胞的NO消耗速率可以通过细胞骨架结合蛋白如带3扰乱细胞骨架网络来调节。尤其是。铁-亚硝基-血红蛋白[HbFe（II）NO]（~ 0.1%）的形成增加了NO消耗速率。该调节剂具有生理和病理重要性，因为HbFe（II）NO在缺氧期间形成，并且已经在各种条件下在人体中检测到。因此，本申请的目的是研究亚硝酰Hb介导的调节的生化机制，并确定其生理/病理作用。假设处于“超T”状态的HbFe（II）NO与带3结合并将其群体转变为二聚体形式，这使细胞骨架网络松散。由于HbFe（II）NO可在缺氧下在肺中产生，因此HbFe（II）NO调节的NO消耗可参与缺氧性肺血管收缩。此外，基于初步数据，进一步假设HbFe（II）NO减弱NO介导的冠状血管舒张。具体目标1将使用探测细胞骨架和带3蛋白的状态的生物化学和生物物理技术来研究参与这种调节的机制。具体目标2将集中于使用离体猪肺和冠状动脉微血管的这种调节的功能作用。总之，这些结果将表明临床相关性和潜在的干预措施。

DESCRIPTION (provided by applicant): Nitric oxide (NO) achieves its biological functions through a balance between its synthesis and inactivation. The biosynthesis of NO is highly regulated and well documented, whereas its inactivation is much less understood. The major pathways for NO inactivation include reactions with oxygenated hemoglobin [HbFe (ll) O2] and various free radicals. Conventional wisdom suggests that NO inactivation by HbFe (ll) O2 is not regulated, since NO is thought to diffuse freely and rapidly across the red blood cell (RBC) membrane. Recent findings have shown that NO transport into RBCs is controlled by the membrane skeleton proteins. The rate of NO consumption by RBCs can be modulated by perturbing the cytoskeleton network through cytoskeleton binding proteins such as Band 3. In particular. formation of iron-nitrosyl-hemoglobin [HbFe (ll) NO] (-0.1%) increased the NO consumption rate. This regulator is of physiological and pathological importance as HbFe (ll) NO is formed during hypoxia and has been detected in humans under various conditions. The purpose of this application is thus to investigate the biochemical mechanisms underlying the nitrosylHb-mediated regulations and to determine their physiological/pathological roles. It is hypothesized that HbFe (ll) NO in the "super T" state binds to Band 3 and shifts its population to the dimer form, which loosens the cytoskeleton network. Since HbFe (ll) NO may be produced in the lungs under hypoxia, the HbFe (ll) NO regulated NO consumption may participate in hypoxic pulmonary vasoconstriction. Moreover, based on preliminary data, it is further hypothesized that HbFe (ll) NO attenuates the NO-mediated coronary vasodilation. Specific aim 1 will investigate the mechanisms involved in this regulation using biochemical and biophysical techniques which probe the state of cytoskeleton and Band 3 protein. Specific aim 2 will focus on the functional roles of this regulation using isolated porcine pulmonary and coronary microvessels. Together, these results will suggest clinical relevance and potential interventions.