SYMPATHETIC RESPONSE DURING 21 DAYS AT HIGH-ALTITUDE (4,300-M) AS DETERMINED BY URINARY AND ARTERIAL CATECHOLAMINES
SYMPATHETIC RESPONSE DURING 21 DAYS AT HIGH-ALTITUDE (4,300-M) AS DETERMINED BY URINARY AND ARTERIAL CATECHOLAMINES
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DOI：
10.1016/0026-0495(94)90215-1
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发表时间：
1994-10-01
影响因子：
9.8
通讯作者：
REEVES, JT
中科院分区：
文献类型：
--
作者：
MAZZEO, RS;WOLFEL, EE;REEVES, JT
交感肾上腺系统在适应短期和长期高海拔暴露中起着重要作用。因此，本研究调查了对照和β -阻断受试者在暴露于4300 m环境3周内血液、尿液和肌肉中的儿茶酚胺反应。11名健康的海平面（SL）居民（年龄26±1岁）在SL和抵达时的休息条件下以及在4,300米（派克峰）的21天内进行了研究。6名受试者服用240毫克/天的心得安，5名受试者服用安慰剂。与SL值（对照端b阻断分别为38.7 +/- 4.3和32.4 +/- 2.8 μ g/d）相比。尿去甲肾上腺素（NE）在高原暴露期间显著增加，在第6 ~ 7天达到峰值（分别为105.5 +/- 16.1和88.4 +/- 12.3 μ g/d）。此外，静息动脉NE水平（向上箭头87%）和净NE释放（向上箭头219%）均在适应过程中增加，表明交感神经活动升高。全身血管阻力和动脉压随海拔时间的增加而增加，并与NE测量值相关。两组受试者的静息心率在海拔4天后开始上升，然后稳步下降。与SL值相比，尿肾上腺素（EPI）排泄量随着初始暴露而增加（对照组为5.1 +/- 0.8至6.6 +/- 0.7 μ g/d， β阻断组为4.5 +/- 0.5至5.2 +/- 1.3 μ g/d）；然而，在接下来的20天里，没有观察到一致的模式。急性暴露时动脉EPI升高，驯化21天后下降。多巴胺排泄未因β阻断或海拔暴露而发生变化。结论是，尽管交感神经和肾上腺活动不同，但交感神经肾上腺活动的改变与高原适应相关的几种心血管调节有关。版权所有(C) 1994由W.B.桑德斯公司
The sympathoadrenal system plays a major role in adjustments to both short- and long-term high-altitude exposure. Thus, this study investigated catecholamine responses in blood, urine, and muscle during 3 weeks' exposure to 4,300 m in control and beta-blocked subjects. Eleven healthy, sea level (SL)-resident men (aged 26 +/- 1 years) were studied under resting conditions at SL and on arrival and during 21 days at 4,300 m (Pikes Peak). Six subjects received 240 mg/d propranolol, and five were administered a placebo. Compared with SL values (38.7 +/- 4.3 v 32.4 +/- 2.8 mu g/d for control end B-blocked, respectively). urinary norepinephrine (NE) excretion increased significantly during altitude exposure, reaching peak values on days 6 to 7 (105.5 +/- 16.1 v 88.4 +/- 12.3 mu g/d, respectively). Furthermore, resting arterial NE levels (up arrow 87%), as well as net NE release (up arrow 219%) across the leg, both increased during acclimatization, indicating elevated sympathetic activity. Systemic vascular resistance and arterial pressures increased with time at altitude and correlated with NE measurements. Resting heart rates increased initially and then declined steadily after day 4 at altitude in both groups of subjects. Urinary epinephrine (EPI) excretion increased with initial exposure as compared with SL values (5.1 +/- 0.8 to 6.6 +/- 0.7 mu g/d for control, 4.5 +/- 0.5 to 5.2 +/- 1.3 mu g/d for beta-blocked); however, no consistent pattern was observed for the following 20 days at altitude. Arterial EPI increased upon acute exposure, but declined after 21 days' acclimatization. No changes in dopamine excretion were observed with beta blockade or altitude exposure. It was concluded that although sympathetic and adrenal activity differ, alterations in sympathoadrenal activity correlate with several cardiovascular adjustments associated with acclimatization to high altitude. Copyright (C) 1994 by W.B. Saunders Company