ARTERIAL WALL 02 AT BIFURCATIONS AND STENOSES

脑血管疾病是美国第三大死亡原因 是中风的主要原因。 动脉壁缺氧 引发和/或加重疾病过程的作用。 这 一项研究项目将调查动脉壁氧含量 血流动力学损伤后供应减少。 一种协同方法将是 采取，结合组织学研究，氧和pH微电极 学习和理论计算机研究。 将获得测量结果 在体外良好控制的条件下，使用分离的、灌注的颈动脉 正常家兔动脉和腹主动脉段（对照组1）， 以及颈动脉（组2）或腹部 主动脉（第3组）已通过手术缩小直径， 一根丝线 狭窄将在手术前1至3个月进行。 实验研究，允许时间的血流动力学损伤和改变 血管壁的特性。 组织耗氧率， 扩散系数和溶解度系数将由下式估算： 氧微电极数据。 缺氧时乳酸的积累会 根据用pH微电极测量的组织pH变化估计。 测量地点将包括（a） 狭窄，（B）近端和（c）远端部位。 一种标记技术， 微电极尖端将用于识别部位。 解剖和 实验参数将用于计算机模拟，以预测如何 在其它条件下，对壁的氧气供应将改变。 的 微电极技术和理论建模， 研究项目将为继续开展有关工作提供基础。 与吸烟相关的动脉壁病理学，致动脉粥样硬化 饮食、糖尿病、高血压等危险因素。 长期 目的是提供新的信息，可用于评估 缺氧可加速动脉粥样硬化过程的机制，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.