Giesbrecht G G, Fewell J E, Megirian D, Brant R, Remmers J E
Department of Medical Physiology, University of Calgary, Alberta, Canada.
J Appl Physiol (1985). 1994 Aug;77(2):726-30. doi: 10.1152/jappl.1994.77.2.726.
Cold exposure elicits several thermoregulatory responses, including an increased metabolic heat production from shivering and nonshivering thermogenesis. The increased metabolism can be in response to body core and/or body cutaneous cooling. Hypoxic hypoxia has been shown to attenuate the metabolic response to cutaneous cooling. We measured metabolic heat production in adult conscious rats during independent cutaneous and core cooling, during normoxia and hypoxia, to 1) test the hypothesis that hypoxia suppresses the metabolic response to independent core cooling and 2) determine whether hypoxia acts preferentially on the response to cutaneous or core cooling. The animals were studied in a temperature-controlled metabolic chamber, and body core temperature was controlled by an abdominal heat exchange coil. Ambient temperature was varied (10, 19, and 28 degrees C) while core temperature was clamped at 37 degrees C or core temperature was varied (33, 35, and 37 degrees C) at a stable ambient temperature of 28 degrees C. Our data indicate that although the sensitivity of the metabolic response to core cooling is about five to six times that to cutaneous cooling. Hypoxia similarly attenuates thermoregulatory responses to both stimuli.
冷暴露会引发多种体温调节反应，包括寒战产热和非寒战产热导致的代谢产热增加。代谢增加可能是对身体核心和/或体表降温的反应。低氧性缺氧已被证明会减弱对体表降温的代谢反应。我们在常氧和低氧条件下，对成年清醒大鼠进行独立的体表和核心降温时测量代谢产热，以1）检验低氧抑制对独立核心降温的代谢反应这一假设，以及2）确定低氧是否优先作用于对体表或核心降温的反应。在温度可控的代谢室中研究动物，通过腹部热交换线圈控制身体核心温度。环境温度变化（10、19和28摄氏度），同时将核心温度维持在37摄氏度，或者在28摄氏度的稳定环境温度下改变核心温度（33、35和37摄氏度）。我们的数据表明，尽管代谢反应对核心降温的敏感性约为对体表降温的五到六倍。低氧同样会减弱对两种刺激的体温调节反应。
