Thermoregulatory responses of prepubertal boys and young men in changing temperature linearly from 28 to 15°C
Thermoregulatory responses of prepubertal boys and young men in changing temperature linearly from 28 to 15°C
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青春期前男孩和年轻男性在 28°C 至 15°C 线性温度变化下的体温调节反应
DOI：
10.1007/bf00838639
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
J. Tsujita
中科院分区：
文献类型：
--
作者：
Y. Inoue;T. Araki;J. Tsujita
摘要：为了检查青春期前儿童对冷应激的体温调节反应，11 名男孩（8 岁）和 11 名年轻男性（19-23 岁）只穿着泳裤参加了这项研究。他们在 28°C 的空气中放置 30 分钟（平衡期），然后在空气温度 (Ta) 从 28°C 线性降低到 15°C（以 0.22°C·min−1 的恒定速率）的条件下保持 60 分钟，固定相对湿度为 65%。在平衡期，各组之间的直肠温度 [Tre，男孩和男性的平均值分别为 37.30 (SEM 0.10) 和平均值 37.43 (SEM 0.14)°C] 或各自的皮肤温度（前额除外）没有显着差异，但代谢热产生（
$$\点M$$
）对于男孩来说明显更高[平均值 57.1 (SEM 1.2) 和平均值 52.0 (SEM 0.9)W。 m−2,P <0.005]。随着Ta的下降，两组皮肤温度均下降（P<0.001），但男孩的下降幅度明显更大（P<0.05），尤其是以大腿和前臂为代表的四肢。与两组的表面积质量比或肢体皮褶厚度相比，没有观察到肢体皮肤温度之间存在显着相关性。增长率为
$$\点M$$
男孩的 asTa 下降幅度显着较低 (P < 0.01)，主要是因为男孩的 asTa 下降幅度较高
$$\点M$$
在冷暴露之前。因此，均值
$$\点M$$
在寒冷暴露期间，各组之间没有差异[男孩和男性的平均值分别为 63.6 (SEM 1.1) 和平均值 61.6 (SEM 1.1) W·m−2]。当Ta降低时，男孩的Tre开始下降（P < 0.001），而年轻男性的Tre在60分钟内没有变化。男孩在 60 分钟暴露期间的 Tre 显着较低 (P < 0.001) [暴露结束时平均为 37.01 (SEM 0.13)°C 和平均 37.48 (SEM 0.18)°C]。结论是，当 Ta 降低时，与年轻人相比，青春期前男孩的四肢血管收缩更多，体温也更低。
AbstractTo examine thermoregulatory responses of prepubertal children to cold stress, 11 boys (aged 8 years) and 11 young men (aged 19–23 years), wearing only trunks, participated in this study. They sat in air at 28°C for 30 min (equilibrium period) and then in conditions where air temperature (Ta) was decreased linearly from 28 to 15°C (at a constant rate of 0.22°C · min−1) for 60 min, at a fixed relative humidity of 65%. In the equilibrium period there was no significant difference between the groups for rectal temperature [Tre, mean 37.30 (SEM 0.10) and mean 37.43 (SEM 0.14)°C in the boys and the men, respectively] or for the respective skin temperatures (except for the forehead), but metabolic heat production (
$$\dot M$$
) was significantly greater for the boys [mean 57.1 (SEM 1.2) and mean 52.0 (SEM 0.9)W. m−2,P <0.005]. With decliningTa, the skin temperatures decreased in both groups (P <0.001), but the decrease was significantly greater for the boys (P < 0.05), especially on the limbs as represented by the thigh and forearm. No significant correlations were observed between the limb skin temperatures compared to surface area-to-mass ratio or limb skinfold thicknesses in either group. The rate of increase in
$$\dot M$$
asTa decreased was significantly lower for the boys (P < 0.01) largely because of a higher
$$\dot M$$
before the cold exposure. Thus, the mean
$$\dot M$$
during the cold exposure did not differ between the groups [mean 63.6 (SEM 1.1) and mean 61.6 (SEM 1.1) W · m−2 in boys and men, respectively]. When theTa was lowered,Tre in the boys started falling (P < 0.001), whereas theTre in the young men did not change for 60 min. TheTre during the 60-min exposure was significantly lower (P < 0.001) for the boys [mean 37.01 (SEM 0.13) and mean 37.48 (SEM 0.18)°C at the end of the exposure]. It was concluded that whenTa was lowered, the prepubertal boys appeared to vasoconstrict more in their limbs and to be somewhat more hypothermic, compared to the young men.