MECHANISM OF CORONARY ENDOTHELIUM MEDIATED VASODILATION

内皮依赖性血管舒张在血管内皮细胞的增殖中起重要作用。 控制冠状血管张力。内皮源性 超极化因子、环氧类二十烷酸（Epoxyeicosanoids，ESTs）和内皮- 据报道，衍生的松弛因子一氧化氮（NO） 激活血管平滑肌K+通道，扩张冠脉 船舶.然而，E2和NO激活K+的机制 渠道仍然未知。最近，几个重要的观察 这表明细胞内ADP-核糖可能作为一种新的第二 信使来调节非血管组织中的细胞功能。我们 初步研究结果还表明，环ADP-核糖和ADP- 核糖可能参与冠状动脉钾通道的门控 平滑肌和内皮细胞改变这些信号的代谢 个核苷酸拟议研究的目的是确定 环ADP核糖和ADP核糖在钾离子门控中的作用 （K+）通道在血管平滑肌细胞分离的小 冠状动脉和这些核苷酸的贡献， 内源性血管舒张剂如雌二醇和一氧化氮对钾通道作用 活动和血管张力。我们将首先描述 冠状动脉平滑肌cADP-R和ADP-R代谢途径 肌肉和定义的动力学特性和调节机制， 这些途径中的关键酶。这些新的核苷酸将是 使用离子对反相HPLC技术测量， 将使用质谱法鉴定结构。淋巴细胞 分化抗原CD 38具有多种活性，包括 将检测到环状ADP-核糖的产生和水解， 冠状动脉的血管平滑肌。我们将决定 环ADP-核糖和ADP-核糖在K+通道门控中的作用， 定义由环状ADP-核糖门控的K+通道的类型， ADP-核糖膜片钳技术。我们亦会探讨 环状ADP-核糖和ADP-核糖门控K+的分子机制 渠道最后，我们将确定是否环ADP-核糖或ADP- 核糖有助于内皮衍生的血管扩张剂的作用。 环腺苷二磷酸核糖和腺苷二磷酸核糖在钾通道激活中的作用 将检测E2和NO诱导的细胞凋亡。这些研究将证明 一种新的内皮源性细胞因子作用的信号通路 血管扩张剂，有助于我们理解细胞和 门控钾通道和调节冠状动脉血管的分子机制 语气

Endothelium-dependent vasodilation plays an important role in the control of coronary vascular tone. An endothelium-derived hyperpolarization factor, epoxyeicosanoids (EETs) and an endothelium- derived relaxation factor, nitric oxide (NO) have been reported to activate K+ channel in vascular smooth muscle and dilate coronary vessels. However, the mechanism by which EETs and NO activate K+ channels remains unknown. Recently, several important observations suggest that intracellular ADP-riboses may serve as a new second messenger to regulate cell functions in non-vascular tissues. Our preliminary findings also indicate that cyclic ADP-ribose and ADP- ribose may participate in the gating of K+ channel in coronary vascular smooth muscle and EETs alter the metabolism of these signaling nucleotides. The purpose of the proposed studies is to determine the role of cyclic ADP-ribose and ADP-ribose in the gating of potassium (K+) channels in vascular smooth muscle cells isolated from small coronary arteries and the contribution of these nucleotides to the effect of endogenous vasodilators such as EETs and NO, on K+ channel activity and vascular tone. We will first characterize the enzymatic pathways of cADP-R and ADP-R metabolism in coronary vascular smooth muscle and define the kinetic properties and regulatory mechanism of the key enzymes in these pathways. These novel nucleotides will be measured using ion-pair reverse phase HPLC technique and their structure will be identified using mass spectrometry. A lymphocyte differentiate antigen, CD38 which has multiple activities including the production and hydrolysis of cyclic ADP-ribose will be detected in vascular smooth muscle of coronary arteries. We will determine the role of cyclic ADP-ribose and ADP-ribose in the gating of K+ channels and define the type of K+ channels that is gated by cyclic ADP-ribose and ADP-ribose using patch clamp technique. We will also explore the molecular mechanism by which cyclic ADP-ribose and ADP-ribose gate K+ channels. Finally we will determine whether cyclic ADP-ribose or ADP- ribose contributes to the effect of endothelium-derived vasodilators. The role of cyclic ADP-ribose and ADP-ribose in K+ channel activation induced by EETs and NO will be examined. These studies will demonstrate a new signaling pathway for the action of endothelium-derived vasodilators and contribute to our understanding of cellular and molecular mechanism gating K+ channels and regulating coronary vascular tone.