Horowitz J M, Horwitz B A
Department of Animal Physiology, University of California, Davis, California 95616, USA.
Life Sci Space Res. 1978;16:77-82. doi: 10.1016/b978-0-08-022022-2.50015-0.
Rats exposed to 2g environments (achieved by centrifugation) exhibit a decreased ability to maintain colonic temperature (Tco) when challenged with a 1 hr drop in ambient temperature (Ta). As an extension of this work the present study considers whether the altered ability to maintain Tco is proportional to the magnitude of the acceleration field in the range from 1g-4g, and whether the magnitude of the decreased thermoregulatory ability is related to the onset time of the temperature drop relative to that of the acceleration. Male, Sprague-Dawley rats were instrumented on the experimental day with thermistors for measuring Tco. The unanesthetized rat was then placed in a plexiglas chamber, positioned on a centrifuge 1.37 m in radius, and exposed to 1.5, 2, 2.5, 3, 3.5, or 4g for 5-7 hrs. The exposure to reduced temperature (Ta = approximately 7 degrees C) for 1 hr began 3 hrs after initiation of centrifugation. These experiments indicated that the magnitude of the cold-induced drop in Tco was linearly related to the acceleration field. The effect of a specific stressor (cold) on the thermoregulatory system is therefore a direct function of the gravitational field.
暴露于2g环境（通过离心实现）的大鼠，在环境温度（Ta）下降1小时的挑战下，维持结肠温度（Tco）的能力会降低。作为这项工作的延伸，本研究考虑维持Tco的能力改变是否与1g至4g范围内的加速度场大小成正比，以及体温调节能力下降的幅度是否与相对于加速度的温度下降起始时间有关。在实验当天，对雄性Sprague-Dawley大鼠植入用于测量Tco的热敏电阻。然后将未麻醉的大鼠置于一个有机玻璃腔室中，该腔室位于半径为1.37 m的离心机上，并暴露于1.5、2、2.5、3、3.5或4g环境中5至7小时。在离心开始3小时后，开始1小时的低温（Ta约为7摄氏度）暴露。这些实验表明，冷诱导的Tco下降幅度与加速度场呈线性相关。因此，特定应激源（寒冷）对体温调节系统的影响是重力场的直接函数。
