HYPERTENSION: CONTRIBUTION OF ARTERIAL WALL CHANGES

质膜被认为是改变的部位， 兴奋-收缩偶联已知发生在动脉平滑肌中， 高血压受试者，但负责的机制并不完全 明白 所提出的研究是基于这样的假设， 高血压时血管交感神经活动增加 影响Ca 2+和K+的生物物理和药理学性质 质膜中的通道有助于激发的改变- 收缩偶联，这种作用是通过改变 磷脂双层的脂质组成和脂质顺序 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解决 20周龄WKY和SHR的主动脉和肠系膜动脉分支。 目标1： 比较钙离子和钾离子的生物物理和药理学性质 具有质膜脂质（胆固醇和磷脂）分布的通道 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（抗神经生长因子和 在调节离子通道之间的关系 性质和质膜脂质分布和流动性。 的 Ca 2+和K+通道的生物物理学和药理学特性将被 使用全细胞膜片钳方法测定。 的脂质组合物 分离的质膜将用脂质分析法测定。 采用差示超离心分离膜的方法 技术. 测定离体质膜的流动性 从使用膜探针1，6- 二苯基-1，3，5-己三烯。 离子通道性质之间的关系， 并建立质膜脂质谱和流动性（目标1） 多变量方差分析。 交感神经的作用 神经系统对这些关系将通过外周评估 应用新生儿抗神经生长因子联合乙啶行交感神经切除术（目的 2）。 这一程序将与抗高血压的效果进行比较 （肼屈嗪-氢氯噻嗪-普萘洛尔）治疗（目的3）分离 动脉压降低对这些关系的影响。 的 这项研究的目的是证明：a）差异 WKY和SHR之间的Ca ~（2+）和K ~+通道特性存在差异; B）这些 差异与质膜脂质谱的差异有关， 流动性; c）交感神经系统调节这种流动性。 关系，并有助于兴奋收缩的差异 高血压中的偶联;以及d）差异是由于 交感神经系统对质膜脂质组成的影响。

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.