| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Sleep Disorders Section, Divisions of Endocrinology and Pulmonary and Critical Care Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, 02115
Although pharyngeal muscles respond robustly to increasing PCO2 during wakefulness, the effect of hypercapnia on upper airway muscle activation during sleep has not been carefully assessed. This may be important, because it has been hypothesized that CO2-driven muscle activation may importantly stabilize the upper airway during stages 3 and 4 sleep. To test this hypothesis, we measured ventilation, airway resistance, genioglossus (GG) and tensor palatini (TP) electromyogram (EMG), plus end-tidal PCO2 (PETCO2) in 18 subjects during wakefulness, stage 2, and slow-wave sleep (SWS). Responses of ventilation and muscle EMG to administered CO2 (PETCO2 = 6 Torr above the eupneic level) were also assessed during SWS (n = 9) or stage 2 sleep (n = 7). PETCO2 increased spontaneously by 0.8 ± 0.1 Torr from stage 2 to SWS (from 43.3 ± 0.6 to 44.1 ± 0.5 Torr, P < 0.05), with no significant change in GG or TP EMG. Despite a significant increase in minute ventilation with induced hypercapnia (from 8.3 ± 0.1 to 11.9 ± 0.3 l/min in stage 2 and 8.6 ± 0.4 to 12.7 ± 0.4 l/min in SWS, P < 0.05 for both), there was no significant change in the GG or TP EMG. These data indicate that supraphysiological levels of PETCO2 (50.4 ± 1.6 Torr in stage 2, and 50.4 ± 0.9 Torr in SWS) are not a major independent stimulus to pharyngeal dilator muscle activation during either SWS or stage 2 sleep. Thus hypercapnia-induced pharyngeal dilator muscle activation alone is unlikely to explain the paucity of sleep-disordered breathing events during SWS.
obstructive sleep apnea syndrome; dilator muscle; genioglossus; hypercapnia; slow-wave sleep; nonrapid eye movement
This article has been cited by other articles:
|
|
 |
|
  M. Younes Role of respiratory control mechanisms in the pathogenesis of obstructive sleep disorders J Appl Physiol, November 1, 2008; 105(5): 1389 - 1405. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. R. Schwartz, S. P. Patil, A. M. Laffan, V. Polotsky, H. Schneider, and P. L. Smith Obesity and Obstructive Sleep Apnea: Pathogenic Mechanisms and Therapeutic Approaches Proceedings of the ATS, February 15, 2008; 5(2): 185 - 192. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Younes, M. Ostrowski, R. Atkar, J. Laprairie, A. Siemens, and P. Hanly Mechanisms of breathing instability in patients with obstructive sleep apnea J Appl Physiol, December 1, 2007; 103(6): 1929 - 1941. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Y.-L. Lo, A. S Jordan, A. Malhotra, A. Wellman, R. A Heinzer, M. Eikermann, K. Schory, L. Dover, and D. P White Influence of wakefulness on pharyngeal airway muscle activity Thorax, September 1, 2007; 62(9): 799 - 805. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. Chan, H. W. Steenland, H. Liu, and R. L. Horner Endogenous Excitatory Drive Modulating Respiratory Muscle Activity across Sleep-Wake States Am. J. Respir. Crit. Care Med., December 1, 2006; 174(11): 1264 - 1273. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D. P. Harris, A. Balasubramaniam, M. S. Badr, and J. H. Mateika Long-term facilitation of ventilation and genioglossus muscle activity is evident in the presence of elevated levels of carbon dioxide in awake humans Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2006; 291(4): R1111 - R1119. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. L. Marcus, L. B. Fernandes Do Prado, J. Lutz, E. S. Katz, C. A. Black, P. Galster, and K. A. Carson Developmental changes in upper airway dynamics J Appl Physiol, July 1, 2004; 97(1): 98 - 108. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. B Fogel, J. Trinder, A. Malhotra, M. Stanchina, J. K Edwards, K. E Schory, and D. P White Within-Breath Control of Genioglossal Muscle Activation in Humans: Effect of Sleep-Wake State J. Physiol., August 1, 2003; 550(3): 899 - 910. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Schneider, S. P. Patil, S. Canisius, E. A. Gladmon, A. R. Schwartz, C. P. O'Donnell, P. L. Smith, and C. G. Tankersley Hypercapnic duty cycle is an intermediate physiological phenotype linked to mouse chromosome 5 J Appl Physiol, July 1, 2003; 95(1): 11 - 19. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. L. Stanchina, A. Malhotra, R. B. Fogel, N. Ayas, J. K. Edwards, K. Schory, and D. P. White Genioglossus Muscle Responsiveness to Chemical and Mechanical Stimuli during Non-Rapid Eye Movement Sleep Am. J. Respir. Crit. Care Med., April 1, 2002; 165(7): 945 - 949. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. L. Horner, X. Liu, H. Gill, P. Nolan, H. Liu, and S. Sood Functional Genomics of Sleep and Circadian Rhythm: Selected Contribution: Effects of sleep-wake state on the genioglossus vs. diaphragm muscle responses to CO2 in rats J Appl Physiol, February 1, 2002; 92(2): 878 - 887. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. MALHOTRA, G. PILLAR, R. B. FOGEL, J. K. EDWARDS, N. AYAS, T. AKAHOSHI, D. HESS, and D. P. WHITE Pharyngeal Pressure and Flow Effects on Genioglossus Activation in Normal Subjects Am. J. Respir. Crit. Care Med., January 1, 2002; 165(1): 71 - 77. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
