EFFECTS OF AGE ON LIMB ARTERIAL COMPLIANCE

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。血管系统中许多不同类型的变化可能是人类血管功能随年龄增长而下降的核心。这种功能下降的一个关键因素似乎是血管壁机械性能的变化，以及它们如何对血压变化做出反应。血管的顺应性是指血管对内部压力变化的可扩张性，即每次心脏跳动时血管壁移动的程度。我们开发了一种软件，可以同时记录非侵入性血压监测器的血压轨迹和每次心脏跳动时非侵入性表面应变仪的小腿体积变化，以得出整个小腿的顺应性。该项目将把这项技术与通常使用多普勒超声和无创血压监测评估单个血管顺应性的方法相结合，以比较整个小腿的顺应性与供应小腿血管床的主要动脉--月国动脉的顺应性。这样做是为了比较年龄相关的血管顺应性变化(来自多普勒成像和血压跟踪)与与年龄相关的整个肢体顺应性的变化(来自表面应变计和血压跟踪)，这反映了肢体中大血管和小血管系统的变化，这些变化不容易单独研究。在休息和适度加热(大约一个桑拿浴的温度)时，测量一只小腿和一只脚的局部血流量，而不会引起任何心血管痛苦或不适。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Many different types of changes in the vascular system may be at the heart of decreased blood vessel function with aging in humans. A key factor in this decrement in function appears to be changes in mechanical properties of the vessel walls and how they respond to blood pressure changes. Compliance of blood vessels is their distensibility in response to pressure changes inside them, i.e. how much the vessel walls move every time the heart beats. We have developed a software that can simultaneously record blood pressure tracings from a noninvasive blood pressure monitor and changes in calf volume from a noninvasive surface strain gauge every time the heart beats to derive whole calf compliance. This project will combine this technology with the method generally used to assess single vessel compliance using Doppler ultrasound and noninvasive blood pressure monitoring to compare whole calf compliance with that of the major artery feeding the calf vascular bed, the popliteal artery. This will be done to compare age-related changes in vessel compliance (from Doppler imaging and blood pressure tracings) with age-related changes in whole limb compliance (from surface strain gauge and blood pressure tracings) which reflects changes in the large vessels in the limb and the small vasculature that cannot be easily studied on its own. Measurements will be made during rest and moderate heating (about the temperature of a common sauna) of one calf and foot only to induce a locally higher blood flow without causing any cardiovascular distress or discomfort.