Mechanism of thirst attenuation during head-out water immersion in men.
Mechanism of thirst attenuation during head-out water immersion in men.
复制标题
男性头出水浸泡时口渴减弱的机制。
DOI：
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发表时间：
1995
影响因子：
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通讯作者：
John E. Greenleaf
中科院分区：
文献类型：
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作者：
F. Wada;S. Sagawa;K. Miki;K. Nagaya;S. Nakamitsu;K. Shiraki;John E. Greenleaf
目的是确定细胞外容积或渗透压是否是减少低水分受试者在空气中口渴和头部浸水的主要因素。8名男性（19-25岁）在两种水化条件下接受热中性浸泡和热中性空气，但不进一步饮水：水（Eu-H2O）中的正常水化和空气中的正常水化，以及水（Hypo-H2O）中的水化不足和空气中的水化不足（热运动后重量损失3.7%）。低水组的口渴感在浸泡10 min内降低（P < 0.05），并持续到浸泡10 min后。平均血浆渗透压摩尔浓度（288 +/- 1 mosmol/kgH 2 O）和钠（140 +/- 1 meq/l）保持升高，血浆容量在整个低水期间增加4.2 +/- 1.0%（P < 0.05）。Eu-H_2 O和Hypo-H_2 O时，每搏输出量持续增加（P <0.05），血浆肾素活性迅速持续下降，血浆心钠素持续增加（P < 0.05）。在低浓度H2O时，血浆加压素从5.3 ± 0.7降至2.9 ± 0.5 pg/ml（P < 0.05），但在Eu-H2O时无变化。这些结果表明，持续刺激心房压力感受器和减少dipsogenic刺激细胞外渗透压在Hypo-H2O没有重大改变。因此，它似乎是心肺压力感受器的血管容积诱导的刺激发挥更重要的作用比细胞外渗透压在减少口渴的感觉，在浸泡在低水分受试者。
The purpose was to determine whether extracellular volume or osmolality was the major contributing factor for reduction of thirst in air and head-out water immersion in hypohydrated subjects. Eight males (19-25 yr) were subjected to thermoneutral immersion and thermoneutral air under two hydration conditions without further drinking: euhydration in water (Eu-H2O) and euhydration in air, and hypohydration in water (Hypo-H2O) and hypohydration in air (3.7% wt loss after exercise in heat). The increased thirst sensation with Hypo-H2O decreased (P < 0.05) within 10 min of immersion and continued thereafter. Mean plasma osmolality (288 +/- 1 mosmol/kgH2O) and sodium (140 +/- 1 meq/l) remained elevated, and plasma volume increased by 4.2 +/- 1.0% (P < 0.05) throughout Hypo-H2O. A sustained increase (P < 0.05) in stroke volume accompanied the prompt and sustained decrease in plasma renin activity and sustained increase (P < 0.05) in plasma atrial natriuretic peptide during Eu-H2O and Hypo-H2O. Plasma vasopressin decreased from 5.3 +/- 0.7 to 2.9 +/- 0.5 pg/ml (P < 0.05) during Hypo-H2O but was unchanged in Eu-H2O. These findings suggest a sustained stimulation of the atrial baroreceptors and reduction of a dipsogenic stimulus without major alterations of extracellular osmolality in Hypo-H2O. Thus it appears that vascular volume-induced stimuli of cardiopulmonary baroreceptors play a more important role than extracellular osmolality in reducing thirst sensations during immersion in hypohydrated subjects.