Pascalov-Stoenescu L, Sterescu N
Physiologie. 1975;12(4):291-5.
In 129 infant rats divided into two groups housed to a constant ambient temperature of 21 degrees C, dynamics of body temperature and hypothermic reaction were studied. Beginning with day 1, the experimental group (66 animals), was exposed 15 min. daily for four weeks to an ambient temperature of +40 degrees C. Rectal temperature, temperature of hair-covered skin areas and tail temperature were monitored in either group. A statistically significant difference, which increased with age, between rectal and skin temperature, was found in experimental 3-week-old rats, while in control animals only in 45-day-old ones. Moreover, rectal and skin temperatures in the experimental group were significantly higher than in control group. The body-temperature difference between the two groups disappeared 17 days after cessation of exposure to heat. The hypothermic reaction induced by an weekly 2-min exposure to an ambient temperature of -1 degrees C, was significantly more important and extensive, in the experimental group than in the control one, during the first week of life only. The changes observed suggested a retarded development of the pituitary-corticoadrenal axis.
将129只新生大鼠分为两组，置于21摄氏度的恒定环境温度下，研究体温动态和低温反应。从第1天开始，实验组（66只动物）每天暴露于40摄氏度的环境温度下15分钟，持续四周。两组均监测直肠温度、被毛覆盖皮肤区域的温度和尾巴温度。在3周龄的实验大鼠中发现直肠温度和皮肤温度之间存在统计学上的显著差异，且该差异随年龄增加，而在对照组中仅在45日龄的大鼠中出现这种差异。此外，实验组的直肠温度和皮肤温度显著高于对照组。停止热暴露17天后，两组之间的体温差异消失。仅在出生后的第一周，实验组每周暴露于-1摄氏度的环境温度2分钟所诱导的低温反应，比对照组更显著且更广泛。观察到的这些变化表明垂体-皮质-肾上腺轴发育迟缓。
