EFFECT OF HYPEROSMOLALITY ON CONTROL OF BLOOD-FLOW AND SWEATING
EFFECT OF HYPEROSMOLALITY ON CONTROL OF BLOOD-FLOW AND SWEATING
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DOI：
10.1152/jappl.1984.57.6.1688
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发表时间：
1984-01-01
影响因子：
3.3
通讯作者：
NADEL, ER
中科院分区：
文献类型：
--
作者：
FORTNEY, SM;WENGER, CB;NADEL, ER
为了研究高渗透压对体温调节反应的影响，5 名男性 [平均最大 O2 消耗量 (.ovrhdot.VO2 max) = 48 ml .cntdot。 kg-1 .cntdot。 min-1]在 65-75% .ovrhdot.VO2 max 下在 30°C 下循环长达 30 分钟。 C、40%相对湿度环境3种条件下。首先，进行对照测试 (C)，其中运动前血浆容量 (PV) 和渗透压 (Osm) 平均为 3800 ml 和 282 mosmol .cntdot。分别为kg-1。 Second, exercise tests (D) were performed following dehydration induced by fluid restriction and mild exercise (30% .ovrhdot.VO2 max) in hot (40.degree. C) ambient conditions.然后，每个受试者在进行运动测试之前在凉爽的环境中休息 1 小时。运动前 PV 和 Osm 平均为 3606 ml 和 293 mosmol .cntdot。分别为kg-1。 Third, exercise tests (I) were performed following dehydration, but during the 1-h rest interval, 3% saline was infused so that PV was restored to 3826 ml and Osm averaged 294 mosmol .cntdot.运动前kg-1。 D期间，食道温度（Tes）显着高于C，平均0.56℃。 C 运动 20 分钟后，由于温度为 0.22°C。 C increase in Tes threshold for vasodilation, a 39% reduction in slope of the forearm blood flow (BF)-Tes relationship, a 32% average reduction in maximal exercise BF and a 0.22.degree. C Tes 出汗阈值增加。 During I, responses were similar to D, except the BF-Tes slope and the maximum BF were not significantly different from C. Thus hyperosmolality modifies thermoregulation by elevating thresholds for both vasodilation and sweating even without decreases in PV.
To study the effect of hyperosmolality on thermoregulatory responses, 5 men [average maximal O2 consumption (.ovrhdot.VO2 max) = 48 ml .cntdot. kg-1 .cntdot. min-1] cycled at 65-75% .ovrhdot.VO2 max for up to 30 min in a 30.degree. C, 40% relative humidity environment under 3 conditions. First, control tests (C) were performed where preexercise plasma volume (PV) and osmolality (Osm) averaged 3800 ml and 282 mosmol .cntdot. kg-1, respectively. Second, exercise tests (D) were performed following dehydration induced by fluid restriction and mild exercise (30% .ovrhdot.VO2 max) in hot (40.degree. C) ambient conditions. Each subject then rested in cool surroundings 1 h before performing the exercise test. Preexercise PV and Osm average 3606 ml and 293 mosmol .cntdot. kg-1, respectively. Third, exercise tests (I) were performed following dehydration, but during the 1-h rest interval, 3% saline was infused so that PV was restored to 3826 ml and Osm averaged 294 mosmol .cntdot. kg-1 prior to exercise. During D, esophageal temperatures (Tes) were significantly higher than C, an average 0.56.degree. C after 20 min exercise due to a 0.22.degree. C increase in Tes threshold for vasodilation, a 39% reduction in slope of the forearm blood flow (BF)-Tes relationship, a 32% average reduction in maximal exercise BF and a 0.22.degree. C increase in Tes sweating threshold. During I, responses were similar to D, except the BF-Tes slope and the maximum BF were not significantly different from C. Thus hyperosmolality modifies thermoregulation by elevating thresholds for both vasodilation and sweating even without decreases in PV.