De Vries J, Strubbe J H, Wildering W C, Gorter J A, Prins A J
Department of Animal Physiology, University of Groningen, Haren, The Netherlands.
Physiol Behav. 1993 Feb;53(2):229-35. doi: 10.1016/0031-9384(93)90198-o.
Relationships between feeding and body temperature of rats were investigated at three ambient temperatures during the whole light/dark cycle. Basal liver temperature was negatively correlated with ambient temperature. Only at 29 degrees C liver temperature indicated activation of autonomic and locomotory thermoregulatory responses due to heat stress. At 21 degrees C, liver temperature was always higher than skin temperature. Both showed a clear circadian rhythm with higher values during the dark phase. Meal-associated temperature patterns were superimposed on this circadian rhythm. Liver and skin temperatures showed a preprandial and prandial rise. Liver temperature reached an almost similar peak value just above 39 degrees C at the end of a meal, irrespective of meal size and ambient temperatures of 13 degrees C and 21 degrees C. Liver temperature reached this peak about 2 min earlier and dropped sooner than skin temperature. These results indicate a threshold liver temperature at which feeding activity stops. The present study suggests that temperatures do not exceed this value by adaptive autonomic thermoregulatory responses shifting heat flow from core to skin and by stopping all locomotory activities including feeding, thereby avoiding deterioration of vital organs and physiological processes due to hyperthermia.
在整个光/暗周期内的三种环境温度下，研究了大鼠进食与体温之间的关系。基础肝脏温度与环境温度呈负相关。仅在29℃时，肝脏温度表明由于热应激激活了自主和运动性体温调节反应。在21℃时，肝脏温度始终高于皮肤温度。两者在暗期均呈现明显的昼夜节律，且值更高。与进食相关的温度模式叠加在这种昼夜节律之上。肝脏和皮肤温度在餐前和用餐时升高。无论餐量大小以及环境温度为13℃和21℃，在一餐结束时肝脏温度几乎达到相似的峰值，略高于39℃。肝脏温度比皮肤温度早约2分钟达到该峰值，且下降得更快。这些结果表明存在一个肝脏温度阈值，超过该阈值进食活动就会停止。本研究表明，通过适应性自主体温调节反应将热量从核心转移到皮肤，并停止包括进食在内的所有运动活动，温度不会超过该值，从而避免重要器官和生理过程因体温过高而恶化。
