Department of Environment and Technology, School of Science and Technology, Meijo University, Nagoya, Japan.
J Physiol Anthropol. 2011;30(4):161-7. doi: 10.2114/jpa2.30.161.
The hypothesis tested in the present study is a seasonal difference in the core interthreshold zone (CIZ), as we suggested in an earlier study that individual awareness of heat may change the CIZ due to thermoregulatory behavior. A series of human experiments were carried out in a climatic chamber in January and August of 2009 and January of 2010. The air temperature in the chamber was controlled at 20-24°C. Subjects wore a water-perfused suit that was perfused with 25°C water at a rate of 600 cc/min. They exercised on an ergometer at 50% of their maximum work rate for 10-15 min until their sweating rate increased and then remained seated without exercise until oxygen uptake increased. Subjects' rectal temperature and skin temperatures at four sites were monitored by thermistors. The sweating rate was measured at the forehead with a sweat rate monitor (SKD 4000, Skinos Co.). Oxygen uptake was monitored with a gas analyzer (Respiromonitor RM-300i, Minato Med. Science Co.). In the 2009 winter experiment, 5 male subjects were exposed to lighting of 36 cd/m(2)/1,050 lx, and in the 2009 summer and 2010 winter experiments, 10 male subjects were exposed to lighting of 18 cd/m2/510 lx. The results showed that the CIZ of 0.69±0.29°C (n=22, data from 2005-2007 experiments) at 36 cd/m(2) and that of 0.37±0.17°C (n=10) at 18 cd/m(2) in summer were greater than the CIZ of 0.37±0.13°C (n=5) at 36 cd/m(2) and that of 0.18±0.17°C (n=10) at 18 cd/m(2) in winter, and thus demonstrated a seasonal difference in the CIZ as well as an effect of lighting conditions on the CIZ.
本研究旨在检验核心过度敏感区（CIZ）是否存在季节性差异。我们曾在早期的研究中提出，个体对热的感知可能会因热调节行为而改变 CIZ。为此，我们在 2009 年 1 月、8 月和 2010 年 1 月于气候室中开展了一系列人体实验。气候室的空气温度控制在 20-24°C。受试者穿着水灌注服，水以 600cc/min 的速度灌注到 25°C 的水中。他们在测功器上以 50%的最大工作速率运动 10-15 分钟，直到出汗率增加，然后静坐不运动，直到耗氧量增加。通过热敏电阻监测受试者的直肠温度和四个部位的皮肤温度。使用汗液速率监测器（SKD 4000，Skinos Co.）测量额部的出汗率。使用气体分析仪（Respiromonitor RM-300i，Minato Med. Science Co.）监测耗氧量。在 2009 年冬季实验中，5 名男性受试者暴露在 36 cd/m²/1050 lx 的光照下，而在 2009 年夏季和 2010 年冬季实验中，10 名男性受试者暴露在 18 cd/m²/510 lx 的光照下。结果表明，在 36 cd/m²光照下，2005-2007 年实验中 CIZ 为 0.69±0.29°C（n=22），夏季为 0.37±0.17°C（n=10），大于在 36 cd/m²光照下，2005-2007 年实验中 CIZ 为 0.37±0.13°C（n=5）和冬季 18 cd/m²光照下 CIZ 为 0.18±0.17°C（n=10），这表明 CIZ 存在季节性差异，光照条件对 CIZ 也有影响。
