VSM CHLCRIDE PERMEABILITY IN HYPERTENTION

高血压是心血管疾病发展的主要危险因素 疾病，即中风、心力衰竭和外周血管疾病。 遗传性和盐皮质激素-氯化钠高血压动物的动脉 已知表现出稳态氯离子周转量的增加和 血管收缩反应性。氯离子与血管的关系 收缩还没有明确的定义。建议的研究计划 侧重于改变氯离子的细胞/分子机制 血管通透性及其对血管反应性增加的贡献 高血压。总体计划旨在探索生理作用 特定的氯转运体/通道在调节跨膜信号中的作用 与收缩激动剂有关的事件(钙离子、pH值、膜电位) 动脉血管平滑肌细胞(VSMC)的刺激作用 (主动脉、尾动脉)正常血压、自发性高血压(氯化钠- 敏感和耐药菌株)，以及醛固酮-氯化钠高血压。 荧光显微镜与新开发的数字成像技术相结合 方法，膜片钳技术将用于探测分子 VSMC氯离子稳态的机制。 具体的目标是：1)确定参与氯-的细胞通路 培养的和新鲜分离的VSMC的动态平衡。离子选择性 荧光染料、荧光显微镜和膜片钳技术将 用于详细分析完整的不同的氯离子转运体/通道， 单一VSMC；2)确定氯离子参与的分子机制 传输器/通道激活。结合荧光显微镜 将使用数字图像分析方法和膜片钳技术 同时测量氯离子电导率和时间电导 激动剂刺激后的不同离子；3)探索 VSMC氯离子通透性升高的细胞/分子机制 以及它对提高VSMC反应性的贡献。此外，我们还将 评估氯离子渗透性增加对增强的贡献 不同氯离子流量对主动脉和尾动脉血管反应性的影响 抑制剂。这些研究将有助于我们对 VSMC离子正常和改变的细胞/分子机制 通透性与血管平滑肌细胞功能障碍在血管内皮细胞损伤中的关系 高血压、动脉粥样硬化和动脉血管痉挛。

Hypertension is a major risk factor for the development of cardiovascular disease, i.e., stroke heart failure and peripheral vascular disease. Arteries from animals with genetic and mineralocorticoid-NaCl hypertension are known to exhibit increases in steady-state Cl- turnover and vasoconstrictor responsiveness. The relationship between Cl- and vascular contraction has not been clearly defined. The proposed research program focuses on the cellular/molecular mechanisms underlying altered Cl- permeability and its contribution to increased vascular reactivity in hypertension. The overall plan is designed to probe the physiological role of specific Cl- transporters/channels in modulating transmembrane signaling events (Ca2+, pHi, membrane potential) involved in contractile agonist stimulation of vascular smooth muscle cells (VSMC) isolated from arteries (aorta, caudal artery) of normotensive, spontaneously hypertensive (NaCl- sensitive and resistant strains), and aldosterone-NaCl hypertension. Combination of fluorescence microscopy, newly-developed digital imaging methods, and patch-clamp techniques will be used to probe the molecular mechanisms of VSMC Cl- homeostasis. The specific aims are: 1) Define the cellular pathways involved in Cl- homeostasis in cultured, as well as freshly isolated VSMC. Ion-selective fluorescent dyes, fluorescence microcopy, and patch-clamp techniques will be used to analyze in detail different Cl- transporters/channels in intact, single VSMC; 2) Determine the molecular mechanisms involved in Cl- transporter/channel activation. Fluorescence microscopy in combination with digital image analysis methods and patch-clamp techniques will be used to make simultaneous spatial/temporal measurements of Cl- conductances and different ions following agonists stimulation; 3) Probe the cellular/molecular mechanisms underlying increased VSMC Cl- permeability and its contribution to increase VSMC reactivity. Furthermore, we will evaluate the contribution of increased Cl- permeability to enhanced vascular responsiveness in aorta and caudal artery using different Cl- flux inhibitors. These studies will contribute to our basic understanding of the cellular/molecular mechanisms underlying normal and altered VSMC ion permeability in relationship to VSMC dysfunction in the pathogenesis of hypertension, atherosclerosis and arterial vasospasm.