Changes in thermoregulatory functions of humans after scclimation to heat given daily at a fixed time.

人类在适应每天固定时间的热量后体温调节功能的变化。

• 批准号: 08670077
• 负责人: SHIDO Osamu
• 金额: $ 1.6万
• 依托单位: Kanazawa University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08670077/
• 关键词: heat acclimation; circadian rhythm; sweating; thermoeffector threhsolds; 発汗閾値; 抗利尿ホルモン; アルドステロン; カテコールアミン; 暑熱馴化; 日内リズム

The present project investigated thermoregulatory functions of humans subjected to heat exposure for several hours limited to a fixed time daily.The food ingestion and sleep-awake cycle of volunteers were controlled throughout the experiments. For heat accliamtion, the subjects were exposed to an ambient temperature (Ta) of 46ﾟC for 4 hrs (14 : 00-18 : 00 h) daliy.Experiment 1 : Core temperature (Tcor) of the subjects were measured for 24 h at a constant Ta of 27ﾟC with or without heat acclimation. The pattern of day-night variations of Tcor was altered by heat acclimation, i.e., the Tcor levels were maintained at low levels in the afternoon.Experiment 2 : The subjects were seated in a chair at Ta of 28ﾟC.Both legs were immersed in a warm water and sweating was induced. The procedure was repeated twice in the day, once in the morning and once in the afternoon, before and after heat acclimation. The latency for thermal sweating was shortented and the threshold Tcor for sweating was lowered by heat acclimation only in the afternoon.The results give evidence that in humans, repeated heat exposure limited to a fixed time daily lowers Tcor and alters thermoregulatory functions during the period when the subjects were previously exposed to heat.

本项目研究了人类在每天固定时间内连续暴露数小时的体温调节功能。在整个实验过程中，志愿者的食物摄入和睡眠-觉醒周期都受到控制。热适应：受试者每天暴露在46℃的环境温度（Ta）下4小时（14:00 - 18:00 h）。实验1：在恒温Ta为27ºC的条件下，在热驯化或不热驯化的情况下，测量受试者24 h的核心温度（Tcor）。热驯化改变了tco的昼夜变化模式，即tco在下午维持在较低水平。实验二：受试者坐在温度为28℃的椅子上。将两腿浸泡在温水中，诱导出汗。热驯化前后，每天重复两次，上午一次，下午一次。热驯化仅在下午可缩短热出汗潜伏期，降低热出汗阈值tco。研究结果证明，在人类中，每天固定时间的重复热暴露会降低Tcor，并改变受试者先前暴露在热环境中的体温调节功能。

项目成果

紫藤 治: "暑熱環境への適応-体温調節機能の変化" 地球環境. (in press). (1998)

Osamu Shito：“适应炎热环境 - 体温调节功能的变化”全球环境（1998 年）。

O.Shido et al.: "Thermoeffector thresholds and preferred ambient temperatures of the FOK rat." Am.J.Physiol.(in press). (1998)

O.Shido 等人：“FOK 大鼠的热效应器阈值和首选环境温度。”

O.Shido et al.: "Thermoeffector thresholds and preferred ambient temperatures of the FOK rat" Am.J.Physiol.(in press). (1998)

O.Shido 等人：“FOK 大鼠的热效应器阈值和首选环境温度”Am.J.Physiol.（出版中）。

O.Shido,: "Can our thermoregulatory system anticipate temperature exposure?" Medical hypotheses. (in press). (1998)

O.Shido：“我们的体温调节系统可以预测温度暴露吗？”

O.Shido,: "Can our thermoregulatory system anticipate temperature exposure?" Medical hypotheses.(in press). (1998)

O.Shido：“我们的体温调节系统可以预测温度暴露吗？”