Mercer J B, Jessen C
Pflugers Arch. 1978 Mar 20;373(3):259-67. doi: 10.1007/BF00580833.
Experiments were performed to investigate the effect of general body core cooling on heat production at various air temperatures between +1 degree C and +56 degrees C in conscious goats. An intravascular heat exchanger (IVHE) was used to alter body core temperature independently of air temperature. Heat loss via the IVHE caused a fall in body core temperature, the extent of which depended on the rate of extraction and air temperature. Irrespective of air temperature the decrease in body core temperature resulted in shivering and an increase in heat production, which eventually balanced the heat loss. During steady state conditions the extra heat production was approximately equal to that lost via the IVHE. The threshold body core temperature at which heat production increased in response to central cooling did not significantly alter with air temperature. However, the slopes of the curves describing this response were smaller at higher than at lower air temperatures, which indicated that central thermosensitivity decreased with increasing air temperature. Irrespective of air temperature the threshold temperatures for shivering were higher and the slopes of the curves were steeper than those previously found with combined cooling of the hypothalamus and spinal cord in the same species which indicated the existence of central thermosensors outside the above two mentioned areas.
开展实验以研究全身核心体温冷却对清醒山羊在+1℃至+56℃不同气温下产热的影响。使用血管内热交换器（IVHE）独立于气温来改变身体核心温度。通过IVHE的热损失导致身体核心温度下降，其下降程度取决于提取速率和气温。无论气温如何，身体核心温度的降低都会导致颤抖和产热增加，最终产热与热损失达到平衡。在稳态条件下，额外的产热大致等于通过IVHE损失的热量。因中枢冷却而使产热增加时的身体核心温度阈值不会随气温显著改变。然而，描述这种反应的曲线斜率在较高气温时比在较低气温时小，这表明中枢热敏感性随气温升高而降低。无论气温如何，颤抖的阈值温度更高，且曲线斜率比之前在同一物种中下丘脑和脊髓联合冷却时发现的更陡，这表明在上述两个区域之外存在中枢热传感器。
