Kamimori Gary H, Ryan Edward J, Otterstetter Ronald, Barkley Jacob E, Glickman Ellen L, Davis Harry Q
Department of Behavioral Biology, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA.
Aviat Space Environ Med. 2009 Apr;80(4):376-80. doi: 10.3357/asem.2336.2009.
Enhanced sympathoadrenal activity has been implicated in the pathogenesis of acute mountain sickness (AMS). This study was designed to examine the time course of circulating catecholamines in individuals with and without AMS.
Subjects were low-altitude residents (10 men, 8 women) who had not been exposed to altitude within the previous 2 mo. They breathed 12% O2 (hypoxia equivalent to 4600 m altitude) for 8 h while seated at rest. AMS was evaluated using Lake Louise scores (LLS) at 0, 1, 3, 5, and 7 h of exposure using a threshold of 3 to define AMS. Blood samples were collected to measure arterial blood gases and oxygen saturation as well as arterial and venous epinephrine (A-EPI and V-EPI) and norepinephrine (A-NE and V-NE).
Eight subjects (44%) developed AMS at some time during the experiment. Blood gases showed no significant difference between subjects with or without symptoms (AMS+ and AMS-, respectively). However, AMS+ subjects showed significantly greater concentrations of A-EPI over the 8 h without any between-group difference in V-EPI. Levels of A-NE were significantly higher at baseline and during the first hour of hypoxia in subjects who later developed AMS. V-NE increased significantly over time among all participants with no difference between groups.
These findings suggest a possible physiological marker for individuals who may be relatively susceptible to AMS and provide additional insight into the sympathoadrenal response to acute hypoxia.
增强的交感肾上腺活动与急性高原病（AMS）的发病机制有关。本研究旨在探讨有和无AMS的个体循环儿茶酚胺的时间进程。
受试者为低海拔居民（10名男性，8名女性），在过去2个月内未暴露于高海拔环境。他们静坐在那里，呼吸12%氧气（相当于海拔4600米的低氧环境）8小时。在暴露0、1、3、5和7小时时，使用路易斯湖评分（LLS）评估AMS，以3分为阈值定义AMS。采集血样以测量动脉血气和血氧饱和度，以及动脉和静脉肾上腺素（A-EPI和V-EPI）和去甲肾上腺素（A-NE和V-NE）。
8名受试者（44%）在实验过程中的某个时间出现了AMS。有症状和无症状受试者（分别为AMS+和AMS-）之间的血气无显著差异。然而，AMS+受试者在8小时内的A-EPI浓度显著更高，而V-EPI在组间无差异。后来出现AMS的受试者在基线和低氧的第一小时内A-NE水平显著更高。所有参与者的V-NE随时间显著增加，组间无差异。
这些发现表明，对于可能相对易患AMS的个体，可能存在一种生理标志物，并为交感肾上腺对急性低氧的反应提供了更多见解。
