Ramirez G, Pineda D O, Bittle P A, Agosti S J, Rabb H A, Dietz J R
Department of Internal Medicine, James A. Haley Veterans Hospital, Tampa, FL 33612, USA.
Aviat Space Environ Med. 1995 Nov;66(11):1063-70.
The sodium excretory capacity of six normal subjects born and raised at moderately high altitude (2600 m) was evaluated at high altitude (HA), and after acute mobilization to sea level (SL). The ability of these individuals to respond to an acute salt load was evaluated by infusing a volume of 100 ml.m-2 body surface area (BSA) of 5% sodium chloride solution over a 30-min time period in both experimental conditions. HA natives were able to excrete a significantly greater salt load at HA than at SL (41.8% vs. 31.6%, respectively, p < 0.05) in 3 h. No changes in plasma atrial natriuretic factor (ANF) concentration were found in either experimental condition. Despite an increase in serum osmolality, no vasopressin (AVP) response was noted either at HA or SL. No correlation between serum AVP levels and urine c-AMP concentrations was found. The enhanced excretory response to a salt load at HA was not explained by the measured hormonal changes. The lack of AVP response to increased serum osmolality, both at HA and SL, in high altitude adapted subjects is presently unexplainable.
对6名在中度高海拔地区（2600米）出生并长大的正常受试者在高海拔（HA）以及急性转移至海平面（SL）后，其钠排泄能力进行了评估。在两种实验条件下，通过在30分钟内输注100 ml.m-2体表面积（BSA）的5%氯化钠溶液，评估这些个体对急性盐负荷的反应能力。在3小时内，高海拔地区的本地人在高海拔时比在海平面时能够排泄出显著更多的盐负荷（分别为41.8%对31.6%，p < 0.05）。在两种实验条件下，血浆心钠素（ANF）浓度均未发现变化。尽管血清渗透压升高，但在高海拔或海平面时均未观察到抗利尿激素（AVP）反应。血清AVP水平与尿c-AMP浓度之间未发现相关性。高海拔时对盐负荷增强的排泄反应无法通过所测量的激素变化来解释。目前，高海拔适应受试者在高海拔和海平面时对抗利尿激素对血清渗透压升高均缺乏反应，这一现象尚无法解释。
