|
|
||||||||
1 Department of Chest Medicine, Erasme University Hospital, and 2 Biomedical Physics Laboratory, Université Libre de Bruxelles, 1070 Brussels, Belgium
Present descriptions of nitric oxide (NO) transport in the lungs use two compartment models: airway compartment without mixing and alveolar compartment with perfect mixing. These models neglect NO molecular diffusion in the airways. To assess the impact of axial diffusion on expired NO profile, we solved a transport equation that incorporated diffusion, convection, and NO sources in the symmetrical Weibel model of the lung. When NO parameters computed from experimental data with the two compartment models are used in our model as NO sources, simulated end-expired NO is 29-45 and 64-78% of experimental values at expiratory flows of 50 and 2,000 ml/s, respectively. These lower values are because of NO axial diffusion: During expiration, NO back diffusion (opposed to convection) prevents some NO from being expired, so a two- to fivefold increase of airway NO excretion is necessary to simulate end-expired NO consistent with experimental data. We conclude that, insofar as a significant amount of NO is produced in small airways, models neglecting NO axial diffusion underestimate excretion in the airways.
gas transport model; nitric oxide production
This article has been cited by other articles:
![]() |
V. Suresh, D. A. Shelley, H.-W. Shin, and S. C. George Effect of heterogeneous ventilation and nitric oxide production on exhaled nitric oxide profiles J Appl Physiol, June 1, 2008; 104(6): 1743 - 1752. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Verbanck, Y. Kerckx, D. Schuermans, W. Vincken, M. Paiva, and A. Van Muylem Effect of airways constriction on exhaled nitric oxide J Appl Physiol, April 1, 2008; 104(4): 925 - 930. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Kerckx, A. Michils, and A. Van Muylem Airway contribution to alveolar nitric oxide in healthy subjects and stable asthma patients J Appl Physiol, April 1, 2008; 104(4): 918 - 924. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. C. George How accurately should we estimate the anatomical source of exhaled nitric oxide? J Appl Physiol, April 1, 2008; 104(4): 909 - 911. [Full Text] [PDF] |
||||
![]() |
P. Condorelli, H.-W. Shin, A. S. Aledia, P. E. Silkoff, and S. C. George A simple technique to characterize proximal and peripheral nitric oxide exchange using constant flow exhalations and an axial diffusion model J Appl Physiol, January 1, 2007; 102(1): 417 - 425. [Abstract] [Full Text] [PDF] |
||||
![]() |
H.-W. Shin, P. Condorelli, and S. C. George Examining axial diffusion of nitric oxide in the lungs using heliox and breath hold J Appl Physiol, February 1, 2006; 100(2): 623 - 630. [Abstract] [Full Text] [PDF] |
||||
![]() |
H.-W. Shin, P. Condorelli, and S. C. George A new and more accurate technique to characterize airway nitric oxide using different breath-hold times J Appl Physiol, May 1, 2005; 98(5): 1869 - 1877. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. F. Gelb, C. F. Taylor, E. Nussbaum, C. Gutierrez, A. Schein, C. M. Shinar, M. J. Schein, J. D. Epstein, and N. Zamel Alveolar and Airway Sites of Nitric Oxide Inflammation in Treated Asthma Am. J. Respir. Crit. Care Med., October 1, 2004; 170(7): 737 - 741. [Abstract] [Full Text] [PDF] |
||||
![]() |
H.-W. Shin, P. Condorelli, C. M. Rose-Gottron, D. M. Cooper, and S. C. George Probing the impact of axial diffusion on nitric oxide exchange dynamics with heliox J Appl Physiol, September 1, 2004; 97(3): 874 - 882. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. Condorelli, H.-W. Shin, and S. C. George Characterizing airway and alveolar nitric oxide exchange during tidal breathing using a three-compartment model J Appl Physiol, May 1, 2004; 96(5): 1832 - 1842. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. C. George, M. Hogman, S. Permutt, and P. E. Silkoff Modeling pulmonary nitric oxide exchange J Appl Physiol, March 1, 2004; 96(3): 831 - 839. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |