DETERMINE VASCULAR RESISTANCE IN ARM DURING LBNP & FOREARM NEGATIVE PRESSURE

点击翻译按钮获取中文摘要

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. This is a pilot study designed to determine the contribution of myogenic tone vs. sympathetic nervous system influences on vascular tone in skeletal muscle vascular beds. Ten healthy subjects ages 18 to 35 will be recruited to undergo procedures to determine vascular resistance in both arms during lower body negative pressure and localized negative pressure in one arm. The hypothesis to be tested is that vascular resistance will be higher in the arm under the influence of both myogenic (negative arm pressure) and sympathetic activity (lower body negative pressure) than the arm under sympathetic influence alone (no negative pressure). Subjects will have their arm and legs subjected to negative pressure according to established methods. Heart rate and blood pressure will be monitored by a finger cuff. Brachial artery flow and diameter will be assessed using a Doppler probe and intravenous catheters will be placed in each arm to monitor norepinephrine levels.