Parisi R A, Edelman N H, Santiago T V
Department of Medicine, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, New Brunswick 08903-0019.
Am Rev Respir Dis. 1992 Apr;145(4 Pt 1):832-6. doi: 10.1164/ajrccm/145.4_Pt_1.832.
The ventilatory response to CO2 decreases during slow-wave sleep (SWS) and rapid-eye-movement (REM) sleep compared with awake levels. However, it is not known to what extent this can be attributed to decreased sensitivity of the CO2 chemoreflex. Mechanical factors during sleep may decrease ventilatory output, or PCO2 at the central chemoreceptor may not increase to the same degree as PaCO2, particularly during REM sleep when brain blood flow (BBF) is increased. In 10 goats, we measured the ventilatory (VI), diaphragmatic electromyogram (EMGdI), and BBF responses to CO2 rebreathing during each sleep-wake state. delta VI/delta PaCO2 decreased from wakefulness to SWS (p less than 0.05) and REM sleep (p less than 0.05). In contrast, delta EMGdI/delta PaCO2 was decreased only during REM sleep (p less than 0.05). Concurrently, delta BBF/delta PaCO2 increased during REM sleep (p less than 0.05) compared with the awake state or SWS. A significant reciprocal correlation existed between delta EMGdI/delta PaCO2 and delta BBF/delta PaCO2 across sleep states (r = -0.786). When EMGdI was related to directly measured cerebral venous PCO2 (n = 4), a single linear function (r = 0.894) was found, independent of sleep-wake state. Similar results were obtained during quasi-steady-state hypercapnia. We conclude that central CO2 chemosensitivity is intact during sleep.
与清醒状态相比，慢波睡眠（SWS）和快速眼动（REM）睡眠期间对二氧化碳的通气反应会降低。然而，尚不清楚这在多大程度上可归因于二氧化碳化学反射敏感性的降低。睡眠期间的机械因素可能会降低通气输出，或者中枢化学感受器处的PCO2可能不会像动脉血二氧化碳分压（PaCO2）那样升高到相同程度，尤其是在REM睡眠期间脑血流量（BBF）增加时。在10只山羊中，我们测量了每种睡眠-清醒状态下对二氧化碳再呼吸的通气（VI）、膈肌肌电图（EMGdI）和BBF反应。从清醒到SWS（p<0.05）和REM睡眠（p<0.05），ΔVI/ΔPaCO2降低。相比之下，仅在REM睡眠期间ΔEMGdI/ΔPaCO2降低（p<0.05）。同时，与清醒状态或SWS相比，REM睡眠期间ΔBBF/ΔPaCO2增加（p<0.05）。在不同睡眠状态下，ΔEMGdI/ΔPaCO2与ΔBBF/ΔPaCO2之间存在显著的负相关（r = -0.786）。当EMGdI与直接测量的脑静脉PCO2相关时（n = 4），发现了一个单一的线性函数（r = 0.894），与睡眠-清醒状态无关。在准稳态高碳酸血症期间也获得了类似的结果。我们得出结论，睡眠期间中枢二氧化碳化学敏感性是完整的。
