Bertin R, De Marco F, Mouroux I, Portet R
Laboratorie d'Adaptation Energétique à l'Environment, Ecole Pratique des Hautes Etudes, Paris, France.
J Dev Physiol. 1993 Jan;19(1):9-15.
A comparative chronological study (from 1 to 33 days post partum) was performed to establish the capacity for nonshivering thermogenesis (NST) in rats born and reared at 28 degrees C and at 16 degrees C. The resting metabolism measured at 33 degrees C was higher in the 16 degrees C rats than in the 28 degrees C rats from the 3rd day. When expressed per weight or per surface area units it was higher in 16 degrees C pups than in 28 degrees C pups until the end of the 3rd week. In fact the resting metabolism was significantly proportional to different powers of weight (W0.67 at 16 degrees C and W0.75 at 28 degrees C) during the suckling period. At birth, respiratory quotient (RQ) was the same in both groups (0.70); it increased slowly to the end of the 3rd week (about 0.80). During the 3rd week RQ was lower in 16 degrees C rats than in 28 degrees C animals. This indicates that 16 degrees C rats are more dependent on the milk supplied by their mother. After weaning there were no differences in RQ values (0.90). Rectal temperature was low in both groups on day 1 (about 32 degrees C). It increased until weaning when it stabilized at 37 degrees C. From day 1 to day 18, it was significantly lower in cold reared rats. The capacity for NST was measured by investigating the effect of an injection of norepinephrine (NE) on the metabolic rate at 33 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)
进行了一项比较性的时间顺序研究（产后1至33天），以确定在28摄氏度和16摄氏度环境下出生并饲养的大鼠的非颤抖性产热（NST）能力。从第3天起，在33摄氏度下测量的静息代谢率，16摄氏度组的大鼠高于28摄氏度组的大鼠。按体重或体表面积单位计算，直到第3周结束，16摄氏度组幼崽的静息代谢率都高于28摄氏度组幼崽。实际上，在哺乳期，静息代谢率与体重的不同幂次显著相关（16摄氏度下为W0.67，28摄氏度下为W0.75）。出生时，两组的呼吸商（RQ）相同（0.70）；到第3周结束时缓慢上升（约0.80）。在第3周期间，16摄氏度组大鼠的RQ低于28摄氏度组动物。这表明16摄氏度组大鼠更依赖母亲提供的乳汁。断奶后，RQ值没有差异（0.90）。两组在第1天的直肠温度都较低（约32摄氏度）。温度一直上升到断奶时稳定在37摄氏度。从第1天到第18天，寒冷环境饲养的大鼠的直肠温度显著更低。通过研究注射去甲肾上腺素（NE）对33摄氏度下代谢率的影响来测量NST能力。（摘要截取自250字）
