Thirst sensations and AVP responses at rest and during exercise-cold exposure
Thirst sensations and AVP responses at rest and during exercise-cold exposure
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DOI：
10.1249/01.mss.0000139901.63911.75
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发表时间：
2004-09-01
期刊：
影响因子：
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通讯作者：
Castellani, JW
中科院分区：
文献类型：
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作者：
Kenefick, RW;Hazzard, MP;Castellani, JW
目的：本研究的目的是：1）确定在寒冷中适度运动期间水分不足（HYPO）对口渴感觉的影响; 2）确定寒冷引起口渴下降的可能机制。研究方法：在研究的第一阶段，8名男性在4 ℃（寒冷）或27 ℃（温和）的环境中以50%VO2max在HYPO或水合正常（EU）状态下行走了4次，穿着T恤、短裤和鞋子。在第二阶段，欧盟或HYPO州的9名男性随机进行了4项试验，包括在27 ℃下站立30分钟，然后在4 ℃或27 ℃的空气中站立30分钟，并在50%VO2max下进行30分钟的跑步机运动。结果：在第一阶段，在寒冷试验期间，在HYPO和EU条件下，在60分钟的运动中口渴感都较低（P < 0.05）。在第2阶段，尽管血浆渗透压升高（P < 0.05），但与HYPO-温和、EU-寒冷和EU-三次试验相比，HYPO-寒冷试验中站立休息30分钟和运动30分钟后口渴感和血浆精氨酸加压素[AVP]同样降低（P < 0.05）。结论：无论是水分充足还是水分不足，在休息和中等强度运动时，冷暴露都会使口渴减轻40%。尽管血浆渗透压升高，但冷暴露期间低水化时的减弱口渴与较低的血浆[AVP]相关。这种口渴和AVP在寒冷中的下降可能是外周血管收缩的结果，介导了中央血容量的增加和中央容量受体的刺激。
Purpose: The purpose of this study was to 1) determine the effect of hypohydration (HYPO) on thirst sensations during moderate exercise in the cold and 2) determine a possible mechanism for a cold-induced decline in thirst. Methods: In the first phase of the study, eight males walked on four occasions, in T-shirts, shorts, and shoes, at 50% VO2max for 60 min in either a 4degreesC (cold) or 27degreesC (temperate) environment in a state of HYPO or euhydration (EU). In the second phase, nine males in states of EU or HYPO randomly performed four trials consisting of 30 min standing at 27degreesC, followed by 30 min of standing and 30 min of treadmill exercise at 50% Of VO2max in either 4degreesC or 27degreesC air. Results: In phase 1, thirst sensations were lower throughout 60 min of exercise (P < 0.05) in both HYPO and EU conditions during the cold trials. In phase 2, despite elevated plasma osmolality (P < 0.05), perception of thirst and plasma arginine vasopressin [AVP] similarly decreased (P < 0.05) after 30-min standing rest and 30-min exercise in the HYPO-cold trial, compared with the HYPO-temperate, EU-cold, and EU-ternperate trials. Conclusions: When either euhydrated or hypohydrated, cold exposure attenuated thirst by up to 40% at rest and during moderate-intensity exercise. The attenuated thirst when hypohydrated during cold exposure was associated with lower plasma [AVP] despite an elevated plasma osmolality. This decline in thirst and AVP in the cold may be the result of peripheral vasoconstriction, mediating an increase in central blood volume and stimulation of central volume receptors.