Vitamin C, glutathione and endothelium derived NO

这一应用是基于这样的假设：细胞内 抗氧化状态是内皮细胞的重要组成部分 功能障碍和动脉粥样硬化和衰老的特征 有助于血管疾病的临床表现。这个 内皮细胞通常维持血管的动态平衡，部分是通过 内皮源性一氧化氮(EDNO)的作用。引人入胜 有证据表明，EDNO的作用对血管特别敏感 氧化应激(氧化剂和抗氧化剂之间的不平衡有利于 前者)。早期研究探讨损伤的机制(S) EDNO的作用涉及抗氧化酶，如超氧化物歧化酶或脂溶酶 只是现在才被探索。这项建议的目的是为了定义角色(S) 维生素C和谷胱甘肽(GSH)是两种主要的细胞内水分- 体内可溶抗氧化剂种类，对内皮功能有影响。 我们将使用人主动脉内皮细胞(HAECs)作为体外实验 模型和我们的指标内皮功能将是生物活性 埃德诺。在追求这个项目的目标时，我们将考虑这两个因素 维生素C和谷胱甘肽在细胞内的作用。这两种化合物都提供了 降低关键细胞功能的当量，并对 细胞内抗氧化剂保护。我们将首先测试维生素C的作用 和GSH在EDNO的作用和使用非应激HAECs的生产中。我们 将决定EDNO作用对细胞内容物的依赖 维生素C和谷胱甘肽的氧化还原状态。一旦建立起来，我们将 研究eNOS活性、辅因子等运行机制 可用性、eNOS、自动失活和NO与超氧化物的相互作用。 维生素C和谷胱甘肽的作用也将在暴露于 生理上相关的氧化应激来源，如超氧化物， 过氧物，或氧化的低密度脂蛋白。最后，维生素C和谷胱甘肽在 EDNO在体内的作用将在豚鼠模型中进行测试。豚鼠 会导致维生素C和/或谷胱甘肽轻度缺乏 膳食药理手段及其对EDNO作用的意义 用生物测定法测定，并与氧化应激标志物相关。 胆固醇喂养将被用作一种生理来源 氧化应激与维生素C和谷胱甘肽的叠加作用 在这个模型中也进行了探索。这些研究应该提供额外的 洞察维生素C和谷胱甘肽在维持血管中的作用(S) 动态平衡，并可能建议治疗策略的患者 动脉粥样硬化性血管疾病。

This application is based upon the hypothesis that intracellular antioxidant status is an important component of the endothelial cell dysfunction and characterizes atherosclerosis and aging and that contributes to the clinical manifestations of vascular disease. The endothelium normally maintains vascular homeostasis, in part, through the action of endothelium-derived nitric oxide (EDNO). Compelling evidence indicates that EDNO action is particularly sensitive to vascular oxidative stress (an imbalance between oxidants and antioxidants in favor of the former). Early research examining the mechanism(s) of impaired EDNO action involved antioxidant enzymes such as SOD or lipid-soluble only now being explored. The goal of this proposal is to define to role(s) of vitamin C and glutathione (GSH), the two principal intracellular water- soluble antioxidant species in vivo, on endothelial function. We will use human aortic endothelial cells (HAECs) as out experimental model and our index endothelial function will be the bioactivity of EDNO. In pursuing the goal of this project, we will consider the dual roles out of vitamin C and GSH within the cell. Both compounds provide reducing equivalents for critical cellular functions and are important for intracellular antioxidant protection. We will first test the role of vitamin C and GSH in EDNO action and production using unstressed HAECs. We will determine the dependence of EDNO action on the cellular content and redox state of vitamin C and GSH. once this is established, we will investigate operative mechanisms such as eNOS activity, cofactor availability, eNOS, auto-inactivation and NO interaction with superoxide. The role of vitamin C and GSH will also be tested in HAECs exposed to physiologically relevant sources of oxidative stress such as superoxide, peroxides, or oxidized LDL. Finally, the roles of vitamin C and GSH on EDNO action in vivo will be tested in guinea pig models. Guinea pigs will be rendered marginally vitamin C and/or GSH deficient through dietary of pharmacologic means and the implications for EDNO action determined using bioassays and related to markers of oxidative stress. Cholesterol -feeding will be employed as a physiologic source of oxidative stress and the superimposed effects of vitamin C and GSH explored in this model as well. These studies should provide additional insight into the role(s) of vitamin C and GSH in maintaining vascular homeostasis and may suggest treatment strategies for patients with atherosclerotic vascular disease.