Osborne S, Milsom W K
Department of Zoology, University of British Columbia, Vancouver, Canada.
Respir Physiol. 1993 Jun;92(3):305-18. doi: 10.1016/0034-5687(93)90015-3.
We examined changes in ventilation and metabolic rate during hypothermia (36-27 degrees C) induced with exposure to helium-oxygen and cold in halothane anesthetized ground squirrels (Spermophilus lateralis) and rats. As a consequence of proportionate decreases in VCO2 and breathing frequency, the VE/VCO2 in both species remained constant. The changes which occurred in breathing pattern were also similar in the two species; an increase in TI and TE along with emergence of apneic periods between breaths at body temperatures below 31 degrees C. VT/TI and TI/TTOT decreased but VT remained constant with progressive hypothermia. The ventilatory responses to hypercapnia and hypoxia decreased to the same extent as the ventilatory and metabolic requirements in the ground squirrel but not the rat. The changes in VE and VCO2 during hypothermia in the ground squirrel predicted well the values observed in deep hibernation. We conclude that regulation of ventilation at reduced body temperatures is tightly coupled to metabolic demand.
我们研究了在氟烷麻醉的地松鼠（侧纹黄鼠）和大鼠中，暴露于氦氧混合气和寒冷环境诱导体温降低（36至27摄氏度）期间通气和代谢率的变化。由于二氧化碳排出量（VCO2）和呼吸频率成比例下降，两个物种的每分通气量与二氧化碳排出量比值（VE/VCO2）保持恒定。两个物种呼吸模式的变化也相似；在体温低于31摄氏度时，吸气时间（TI）和呼气时间（TE）增加，同时呼吸之间出现呼吸暂停期。随着体温逐渐降低，潮气量与吸气时间比值（VT/TI）和吸气时间与总呼吸时间比值（TI/TTOT）下降，但潮气量（VT）保持恒定。地松鼠对高碳酸血症和低氧血症的通气反应下降程度与通气和代谢需求相同，但大鼠并非如此。地松鼠体温降低期间每分通气量（VE）和二氧化碳排出量（VCO2）的变化很好地预测了深度冬眠时观察到的值。我们得出结论，体温降低时通气的调节与代谢需求紧密相关。
