|
|
||||||||
Journal of Applied Physiology, Vol 78, Issue 2 555-561, Copyright © 1995 by American Physiological Society
ARTICLES |
D. A. Sidney and C. S. Poon
Harvard-Massachusetts Institute of Technology Division of Health Sciences and Technology, Cambridge 02139, USA.
To investigate how breathing is controlled during CO2 stimulation, steady-state ventilatory responses to rebreathing through a tube (DS) and inspiring a fixed PCO2 (INH) were compared in healthy human subjects. Tests were performed in hyperoxia with (IRL) and without (NL) an inspiratory resistive load (15 cmH2O.l-1.s at 1 l/s). The mean slope of the minute ventilation (VE)-end-tidal PCO2 relationship was significantly higher in DS-IRL than in INH-IRL [1.86 +/- 0.67 (SD) vs. 1.40 +/- 0.32 l.min-1.Torr-1, P < 0.01], and it was significantly different between INH-NL and INH-IRL (1.64 +/- 0.41 vs. 1.40 +/- 0.32 l.min-1.Torr-1, P < 0.05) but not between DS-NL and DS-IRL (1.85 +/- 0.72 vs. 1.86 +/- 0.67 l.min-1.Torr-1). The slope of the VE-tidal volume relationship was significantly lower in DS-NL than in INH-NL (19.6 +/- 3.8 vs. 21.2 +/- 5.1 min-1, P < 0.05), but other comparisons in breathing pattern between NL and IRL and between DS and INH failed to reach significance. We concluded that 1) alterations in alveolar PCO2 temporal profile by DS could induce changes in VE-end-tidal PCO2 sensitivity and ventilatory pattern, 2) these changes may be modified by increased mechanical impairment resulting from IRL, and 3) carotid chemoreceptor mediation is not necessary for the observed effects of DS.
This article has been cited by other articles:
![]() |
C.-S. Poon and R. L. Johnson Jr Possible Mechanism of Augmented Exercise Hyperpnea in Congestive Heart Failure Response Circulation, November 27, 2001; 104 (22): e131 - e131. [Full Text] [PDF] |
||||
![]() |
T. G. Babb Ventilatory response to exercise in subjects breathing CO2 or HeO2 J Appl Physiol, March 1, 1997; 82(3): 746 - 754. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |