HYPERTENSION--CONTRIBUTION OF ARTERIAL WALL CHANGES

质膜已被认为是 已知的兴奋-收缩偶联发生在大鼠的动脉平滑肌 高血压受试者，但相关机制并不完全 明白了。拟议的研究是基于这样一个假设： 高血压患者对血管的交感神经活动增强 钙、钾离子对其生物物理和药理性质的影响 质膜中促进兴奋变化的通道- 收缩偶联，这种效应是通过改变 中华绒毛虫磷脂双层膜的脂类组成和脂序 质膜。为了验证这一假设，以下具体目标将 使用从胸腔分离的细胞和质膜来处理 20周龄WKY和SHR的主动脉和肠系膜动脉分支。目标1： Ca~(2+)和K~+的生物物理和药理特性比较 具有质膜脂质(胆固醇和磷脂)特征的通道 以及WKY和SHR的物理状态(流动性)。目标2：确定 新生儿交感神经切除术(联合应用抗神经生长因子和 在调节离子通道间关系中的作用 性质，以及质膜脂谱和流动性。这个 钙离子和钾离子通道的生物物理和药理特性 采用全细胞、膜片钳方法测定。海参的脂类成分 分离的质膜将用脂类分析法测定 使用差速超速离心法分离膜的操作 技巧。分离的质膜的流动性将被测定 用膜探头测量荧光各向异性1，6- 二苯基-1，3，5-己三烯。离子通道属性之间的关系， 将建立质膜脂质分布和流动性(目标1) 采用多变量方差分析。同情心的作用 神经系统就会对这些关系进行外周评估 新生儿抗神经生长因子联合金刚乙胺的交感神经切除术(目的) 2)。这项手术将与降压的效果进行比较。 (肼-氢氯噻嗪-普萘洛尔)疗法(目标3)分离 动脉压降低对这些关系的贡献。这个 这项拟议研究的目标是证明：a)差异 存在于WKY和SHR之间的钙离子和钾离子通道特性；b)这些 差异与质膜脂质分布的差异和 流动性；c)交感神经系统对此进行调节 兴奋与收缩的关系及其差异的原因 高血压的偶联性；以及d)这种差异是由于一种影响 交感神经系统对质膜脂质成分的影响。

The plasma membrane has been suggested to be the site of alterations in excitation-contraction coupling known to occur in arterial smooth muscle of hypertensive subjects, but the mechanisms responsible are not completely understood. the proposed studies are based upon the hypothesis that increased sympathetic nerve activity to blood vessels in hypertension influences the biophysical and pharmacological properties of Ca2+ and K+ channels in the plasma membrane contributing to alterations in excitation- contraction coupling, and that this effect is mediated through changes in the lipid composition and lipid order of the phospholipid bilayer of the plasma membrane. To test this hypothesis, the following specific aims will be addressed using cells and plasma membranes isolated from the thoracic aorta and mesenteric artery branches of 20 week old WKY and SHR. Aim 1: To compare the biophysical and pharmacological properties of Ca2+ and K+ channels with plasma membrane lipid (cholesterol and phospholipid) profiles and physical state (fluidity) in WKY and SHR. Aim 2: To determine the effect of neonatal sympathectomy (with anti-nerve growth factor and guanethadine) in modulating the relationship between ion channel properties, and plasma membrane lipid profile and fluidity. The biophysical and pharmacological properties of Ca2+ and K+ channels will be determined using whole cell, patch clamp methods. The lipid composition of isolated plasma membranes will be determined with lipid analytical procedures using membranes isolated by differential ultracentrifugation techniques. The fluidity of isolated plasma membrane will be determined from measurement of fluorescence anisotropy using a membrane probe 1,6- diphenyl-1,3,5-hexatriene. A relationship between ion channel properties, and plasma membrane lipid profile and fluidity will be established (Aim 1) by multivariable analysis of variance. The effect of the sympathetic nervous system on these relations will be assessed by peripheral sympathectomy with neonatal anti-nerve growth factor plus guanethidine (Aim 2). This procedure will be compared with the effects of antihypertensive (hydralazine-hydrochlorothiazide-propranolol) therapy (Aim 3) to separate the contribution of reduced arterial pressure to these relationships. The goals of this proposed research are to demonstrate: a) that differences exist in Ca2+ and K+ channel properties between WKY and SHR; b) that these differences are related to differences in plasma membrane lipid profile and fluidity; c) that the sympathetic nervous system modulates this relationship and contributes to the differences in excitation-contraction coupling in hypertension; and d) that the differences are due to an effect of the sympathetic nervous system on plasma membrane lipid composition.