ARTERIAL WALL 02 AT BIFURCATIONS AND STENOSES

脑血管疾病是美国第三大致死原因 国家和地区是中风的主要原因。动脉壁缺氧可能起作用 在启动和/或加剧疾病过程中发挥作用。这 研究项目将调查动脉壁氧气的假说 血液动力学损伤后，血液供应减少。一个协同的方法将是 拍摄，结合组织学研究、氧气和pH微电极 研究和理论计算机研究。将获得测量结果 在良好控制的条件下，使用分离的、灌流的颈动脉 正常兔的动脉和腹主动脉节段(对照组1)， 取自兔的颈动脉(第2组)或腹部 主动脉(第3组)通过外科手术缩窄血管直径。 一条丝绸绷带。狭窄将在手术前1至3个月内进行 实验研究，为血流动力学损伤和改变留出时间 脉管壁的特性。组织耗氧率， 扩散系数和溶解度系数将由以下公式估计 氧微电极数据。缺氧期间乳酸的积累将是 根据用pH微电极测量的组织pH变化进行估算。 测量地点将包括：(A)下游的分叉 狭窄，(B)近端和(C)远端部位。一种打标技术 微电极尖端将被用来识别位置。解剖学和 将在计算机模拟中使用实验参数来预测 在其他情况下，墙壁的氧气供应将发生变化。这个 微电极技术及其发展的理论模型 研究项目将为继续开展相关工作奠定基础 与吸烟、致动脉粥样硬化相关的动脉壁病理 饮食、糖尿病、高血压等危险因素。从长远来看 目的是提供新的信息，可用于评估 缺氧可能加速动脉粥样硬化进程的机制，以及 以确定预防性干预措施。

Cerebrovascular diseases are the third leading cause of death in the United States and are the primary cause of stroke. Arterial wall hypoxia may play a role in initiating and/or exacerbating the disease process. This research project will investigate the hypothesis that arterial wall oxygen supply is reduced after hemodynamic injury. A synergistic approach will be taken, combining histological studies, oxygen and pH microelectrode studies, and theoretical computer studies. Measurements will be obtained under well controlled conditions in vitro using isolated, perfused carotid artery and abdominal aorta segments from normal rabbits (control group 1), and from rabbits where either the carotid artery (group 2) or the abdominal aorta (group 3) has been surgically stenosed by reducing the diameter with a silk ligature. Stenoses will be made from 1 to 3 months prior to the experimental studies, allowing time for hemodynamic injury and alteration of blood vessel wall properties. Tissue oxygen consumption rates, diffusion coefficients and solubility coefficients will be estimated from oxygen microelectrode data. Lactic acid accumulation during anoxia will be estimated from tissue pH changes measured with pH microelectrodes. Measurement sites will include (a) the bifurcations downstream from the stenosis, (b) proximal and (c) distal sites. A technique for marking microelectrode tips will be used to identify the sites. Anatomical and experimental parameters will be used in computer simulations to predict how oxygen supply to the wall will change under other conditions. The microelectrode techniques and theoretical modeling developed in this research project will provide a basis for continued work on related arterial wall pathology associated with cigarette smoking, atherogenic diet, diabetes, hypertension and other risk factors. The long term objective is to provide new information which can be used to evaluate mechanisms whereby hypoxia may accelerate the atherosclerotic process, and to identify preventative interventions.