RECEPTOR SIGNALING IN POLYPLOID VASCULAR SMOOTH MUSCLE

拟议的研究计划侧重于离子、生化和 血管收缩激动剂(血管紧张素II， Kc1)和生长因子(血小板衍生生长因子)对血管生成的影响 二倍体和多倍体血管平滑肌细胞(VSMC) 分离自不同的血管(大动脉、尾动脉和 肠系膜动脉)血压正常、自发性高血压 DOCA/盐性高血压大鼠。新隔离的，以及 培养的VSMC将用于这些研究。详细的分析 细胞内钙和pH的测定将使用流式细胞术 和新开发的多参数分析方法有关 到荧光比率成像显微镜。具体目标 包括：1)提供对静息状态的逐个细胞的详细分析 胞内钙和pH，以及膜电位，在 流式细胞术检测二倍体/四倍体VSMC。此外, 空间和区域分布的差异(核与 将评估细胞内钙和pH的变化；2) 确定二倍体/多倍体(四倍体、八倍体) 高血压动物的VSMC具有改变的信号 与正常二倍体VSMC相比，信号转导通路。我们 还将比较和对比 血管紧张素II和血小板衍生生长因子对细胞内钙离子和pH的影响 刺激；3)评价细胞-细胞的生理相关性 VSMC二倍体和多倍体群体间的互作； 和4)检查细胞遗传学机制 多倍体VSMC表型的发育。这些研究 应该有助于我们基本理解这些机制 正常和改变的VSMC反应性与 高血压、动脉粥样硬化与动脉粥样硬化的发病机制 血管痉挛。

The proposed research program focuses on ionic, biochemical and cellular mechanisms of vasoconstrictor agonist (angiotensin II, KC1) and growth factor (platelet-derived growth factor) action on diploid and polyploid vascular smooth muscle cells (VSMC) isolated from different blood vessels (aorta, caudal artery and mesenteric artery) of normotensive, spontaneously hypertensive and DOCA/salt hypertensive rats. Freshly isolated, as well as cultured VSMC will be used in these studies. A detailed analysis of cytosolic calcium and pH will be made using flow cytometry and newly developed multiparameter analytical methods related to fluorescence-ratio imaging microscopy. The specific aims include: 1) providing a detailed cell-by-cell analysis of resting cytosolic calcium and pH, as well as membrane potential, in diploid/tetraploid VSMC via flow cytometry. In addition, differences in the spatial and regional distribution (nuclear vs. cytosolic) of cellular calcium and pH will be assessed; 2) determining whether diploid/polyploid (tetraploid, octaploid) VSMC from hypertensive animals possess altered signal transduction pathways as compared to normal diploid VSMC. We will also compare and contrast the regional differences in cytosolic calcium and pH following angiotensin II and PDGF stimulation; 3) evaluating the physiological relevance of cell-cell interactions between diploid and polyploid populations of VSMC; and 4) examining the cytogenetic mechanisms which contribute to the development of the polyploid VSMC phenotype. These studies should contribute to our basic understanding of the mechanisms of normal and altered VSMC responsiveness related to the pathogenesis of hypertension, atherosclerosis and arterial vasospasm.