Netick A, Dugger W J, Symmons R A
J Appl Physiol Respir Environ Exerc Physiol. 1984 May;56(5):1347-54. doi: 10.1152/jappl.1984.56.5.1347.
Eucapnic breathing and ventilatory responses to hypercapnia were studied in seven cats during sleep and wakefulness. No significant differences were found in minute ventilation (VE), alveolar ventilation (VA), or alveolar PCO2 (PACO2) between wakefulness (W) and non-rapid-eye-movement (NREM) sleep, but VA and VE were less during rapid-eye-movement (REM) sleep than W, and PACO2 declined during REM compared with NREM. To test the hypercapnic response, cats were required to rebreathe from a bag containing 6% CO2 and 94% O2 (to eliminate the hypoxic response). The response curve was displaced to the right during NREM and REM; the slope was reduced only during REM to a value about 75% of W and NREM. Eye movements, quantifying phasic REM, were only slightly correlated (negatively) with the deviation of ventilation from the response curve. The hypercapnic response was diminished, not eliminated, during REM, even during phasic REM. The reduced slope arose principally from the failure of the expiratory time to shorten with hypercapnia as during W and NREM. The cat's hypercapnic response compared with the dog's, measured by others with the same methodology, suggests that differences between species may be more crucial than methodology in explaining earlier contradictory results.
在七只猫处于睡眠和清醒状态时，研究了其等碳酸呼吸和对高碳酸血症的通气反应。在清醒（W）和非快速眼动（NREM）睡眠之间，分钟通气量（VE）、肺泡通气量（VA）或肺泡PCO2（PACO2）均未发现显著差异，但快速眼动（REM）睡眠期间的VA和VE低于清醒状态，且与NREM相比，REM期间PACO2下降。为测试高碳酸血症反应，要求猫从装有6% CO2和94% O2的袋子中进行重复呼吸（以消除低氧反应）。在NREM和REM期间，反应曲线向右移位；仅在REM期间斜率降低至约为清醒和NREM状态下的75%。量化REM时相的眼球运动与通气偏离反应曲线的程度仅存在轻微（负）相关。即使在REM时相，REM期间高碳酸血症反应也只是减弱而非消除。斜率降低主要是因为呼气时间不像在清醒和NREM期间那样随高碳酸血症而缩短。与其他采用相同方法测量的狗相比，猫的高碳酸血症反应表明，在解释早期相互矛盾的结果时，物种差异可能比方法更为关键。
