RENAL HUMORAL FACTORS IN RENAL FUNCTION & HYPERTENSION

描述：(改编自《调查者摘要》)：目标是 探讨肾素-血管紧张素系统(RAS)导致 肾内灌注和肾小管滤过-重吸收动力学的变化。 猪肾动脉狭窄可刺激血管紧张素II(Ang Ii)刺激超氧化物、异前列腺素和内皮素(ET)的产生 制作。这些血管收缩剂的区域性生产将导致 皮质缺血并相对保留髓质灌注区。电子 电子束计算机断层扫描(EBCT)，一种非侵入性的三维X射线 研制了具有高时间分辨率的层析成像仪(Imatron c-150) 将被用来定义肾内血流的变化和 管状流型。微血管铸型的计算机分析 将有助于定位微循环的变化。目标#1检查以下方面的变化 肾内血流动力学及其与RAS/氧化反应成分的关系 高血压病猪狭窄侧和对侧肾脏应力级联反应及ET变化 2肾1夹Goldblatt高血压。目标#2确定是否重建 流向狭窄肾脏的血流使肾血流正常化，并使其 狭窄肾和对照肾的肾内分布。取消剪裁是 预计动脉压迅速正常化与血压的变化有关 肾素-血管紧张素转换酶和压力性钠尿。AIM#3评估肾内血流动力学和 单侧局灶性脑损伤患者RAS/氧化应激级联状态的研究 肾血管狭窄。人类的结果与 二肾一肾夹高血压的猪模型。AIM#4检查猪 2例肾高血压和1例肾夹高血压的病因分析 RAS和/或氧化应激与肾内血流之间的关系。目标# 5小剂量血管紧张素转换酶II引起的猪高血压的特征 以及氧化应激和ET在发病机制中的作用。

DESCRIPTION: (Adapted from the Investigator's Abstract): The goal is to investigate the mechanisms by which the renin-angiotensin system (RAS) causes changes in intrarenal perfusion and tubular filtration-reabsorption dynamics. Renal artery stenosis in swine is predicted to stimulate angiotensin II (Ang II) production that stimulates superoxide isoprostane and endothelin (ET) production. Regional production of these vasoconstrictor agents will cause cortical ischemia with relative preservation of medullary perfusion. Electron beam computerized tomography (EBCT), a non-invasive x-ray, 3-dimentional tomographer (Imatron c-150) with high temporal resolution, has been developed recently and will be used to define changes in intrarenal blood flow and tubular flow patterns. A computerized analysis of vascular casts of microfil will help localize changes in the microcirculation. Aim # 1 examines changes in intrarenal hemodynamics and relate them with components of the RAS / oxidative stress cascade and ET in the stenotic and contralateral kidneys of pigs with 2-kidney-1-clip Goldblatt hypertension. Aim # 2 determines if reestablishing blood flow to the stenotic kidney normalizes renal blood flow and its intrarenal distribution in both the stenotic and control kidneys. Unclipping is expected to rapidly normalize arterial pressure is related to changes in the RAS and pressure natriuresis. Aim # 3 assesses intrarenal hemodynamics and status of the RAS/oxidative stress cascades in humans with focal unilateral renovascular stenosis. The human results are compared with measures in the swine model of 2-kidney-1 kidney clip hypertension.Aim # 4 examines swine with 2 kidney and 1 kidney clip hypertension with interventions to dissect causal relations between the RAS and / or oxidative stress and intrarenal flows. Aim # 5 is to characterize hypertension in swine produced by low dose Ang II infusion and the roles of oxidative stress and ET in the pathogenesis.