ALTERED VASCULAR SMOOTH MUSCLE IN HYPERCHOLESTEROLEMIA

描述：(改编自摘要)建议的假设 研究表明，胆固醇的增加会改变心脏的结构和功能。 质膜进而改变阳离子通量和细胞质 离子浓度，从而触发改变血管运动和细胞 扩散。这些研究将结合对来自 正常和胆固醇喂养的兔主动脉，动脉中分离的细胞， 培养血管内皮细胞和平滑肌细胞。目标1将决定 膳食动脉粥样硬化对基础和激动剂活性的影响 跨膜Ca++、K+、Na+运动和胞内游离水平。离子 将测定离体动脉的流量、胞浆钙水平 将在分散的细胞中用Fura-2，胞浆K+和Na+测定 能级将从离子的反向外推到零时间进行估计 外流数据。离子的变化将与血管活性相关 对激动剂和钾通道激动剂的反应。比较将会 在培养的细胞中制造，在那里可以得到更纯净的膜准备。在……里面 此外，微血管对缺血和对K+的反应的变化 朗宁多夫兔心脏激活剂与血压的关系 我们将研究麻醉兔的反应。目标2将衡量 将评估膜脂类、流动性，并由合作者评估 用X射线衍射法测定了膜的结构。这些参数将是 与目标1中的离子通量数据相关联。目标3将检查 正常和高胆固醇血症患者低密度脂蛋白的潜在作用 受试者(以及修饰的低密度脂蛋白)是否有能力引起类似的变化 在离子通量和膜结构上。目标4将确定这些机制 通过以下途径促进血管细胞的增殖 测定钙通道拮抗剂的效力并进行 平行离子通量测量，以及确定 来自富含胆固醇的细胞的条件培养液。

DESCRIPTION: (adapted from the abstract) The hypothesis of the proposed studies is that cholesterol enrichment alters the structure and function of the plasma membrane which, in turn, alters cation fluxes and cytoplasmic ion concentrations, thereby triggering altered vasomotion and cell proliferation. The studies will combine studies in isolated arteries from normal and cholesterol-fed rabbit aorta, isolated cells from the arteries, and cultured smooth muscle and endothelium. Aim 1 will determine the effects of dietary atherosclerosis on basal and agonist activated transmembrane Ca++, K+, and Na++ movements and free cytosolic levels. Ion fluxes will be determined in isolated arteries, cytosolic calcium levels will be determined in dispersed cells with fura-2, cytosolic K+ and Na+ levels will be estimated from back extrapolation to zero time from the ion efflux data. Changes in the ions will be correlated to vasoactive responses to agonists and potassium channel activators. Comparisons will be made in cultured cells where purer membrane preps will be available. In addition, changes in microvascular responses to ischemia as well as to K+ activators in the Langendorff rabbit heart as well as blood pressure responses in the anesthetized rabbit will be studied. Aim 2 will measure membrane lipids, fluidity will be assessed, and a collaborator will assess membrane structure by x-ray diffraction. These parameters will be correlated with the ion flux data in aim 1. Aim 3 will examine the potential role of LDL obtained form normal and hypercholesterolemic subjects (as well as modified LDL) for its ability to cause similar changes in ion fluxes and membrane structure. Aim 4 will determine the mechanisms responsible for the increased proliferation of vascular cells by determining the potency of calcium channel antagonists and performing parallel ion flux measurements, as well as determining the influence of conditioned media from cells enriched with cholesterol.