| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Journal of Applied Physiology, Vol 66, Issue 3 1227-1233, Copyright © 1989 by American Physiological Society
ARTICLES |
P. D. Wagner, J. R. Gillespie, G. L. Landgren, M. R. Fedde, B. W. Jones, R. M. DeBowes, R. L. Pieschl and H. H. Erickson
Department of Medicine, University of California, San Diego, La Jolla 92093.
Arterial hypoxemia has been reported in horses during heavy exercise, but its mechanism has not been determined. With the use of the multiple inert gas elimination technique, we studied five horses, each on two separate occasions, to determine the physiological basis of the hypoxemia that developed during horizontal treadmill exercise at speeds of 4, 10, 12, and 13-14 m/s. Mean, blood temperature-corrected, arterial PO2 fell from 89.4 Torr at rest to 80.7 and 72.1 Torr at 12 and 13-14 m/s, respectively, whereas corresponding PaCO2 values were 40.3, 40.3, and 39.2 Torr. Alveolar-arterial PO2 differences (AaDO2) thus increased from 11.4 Torr at rest to 24.9 and 30.7 Torr at 12 and 13-14 m/s. In 8 of the 10 studies there was no change in ventilation-perfusion (VA/Q) relationships with exercise (despite bronchoscopic evidence of airway bleeding in 3) and total shunt was always less than 1% of the cardiac output. Below 10 m/s, the AaDO2 was due only to VA/Q mismatch, but at higher speeds, diffusion limitation of O2 uptake was increasingly evident, accounting for 76% of the AaDO2 at 13-14 m/s. Most of the exercise-induced hypoxemia is thus the result of diffusion limitation with a smaller contribution from VA/Q inequality and essentially none from shunting.
This article has been cited by other articles:
|
|
 |
|
  M. Vengust, H. Staempfli, L. Viel, and G. Heigenhauser Transvascular fluid flux from the pulmonary vasculature at rest and during exercise in horses J. Physiol., January 15, 2006; 570(2): 397 - 405. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Manohar and T. E. Goetz Intrapulmonary arteriovenous shunts of >15 {micro}m in diameter probably do not contribute to arterial hypoxemia in maximally exercising Thoroughbred horses J Appl Physiol, July 1, 2005; 99(1): 224 - 229. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. J. Padilla, P. McDonough, C. A. Kindig, H. H. Erickson, and D. C. Poole Ventilatory dynamics and control of blood gases after maximal exercise in the Thoroughbred horse J Appl Physiol, June 1, 2004; 96(6): 2187 - 2193. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Manohar, T. E. Goetz, and A. S. Hassan NaHCO3 does not affect arterial O2 tension but attenuates desaturation of hemoglobin in maximally exercising Thoroughbreds J Appl Physiol, April 1, 2004; 96(4): 1349 - 1356. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Manohar, T. E. Goetz, and A. S. Hassan Preexercise hypervolemia does not affect arterial hypoxemia in Thoroughbreds performing short-term high-intensity exercise J Appl Physiol, June 1, 2003; 94(6): 2135 - 2144. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Manohar, T. E. Goetz, A. S. Hassan, T. Depuy, and S. Humphrey Anti-inflammatory agent, dexamethasone, does not affect exercise-induced arterial hypoxemia in Thoroughbreds J Appl Physiol, July 1, 2002; 93(1): 99 - 106. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. D. Wagner, P. Wilkins, R. Gleed, A. Dobson, and N. Krivitski Exercise, extravascular lung water, and gas exchange J Appl Physiol, May 1, 2002; 92(5): 2224 - 2225. [Full Text] [PDF]
|
|
|
|
|
|
R. G. Presson Jr., W. A. Baumgartner Jr., A. J. Peterson, R. W. Glenny, and W. W. Wagner Jr. Pulmonary capillaries are recruited during pulsatile flow J Appl Physiol, March 1, 2002; 92(3): 1183 - 1190. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. A. Wilkins, R. D. Gleed, N. M. Krivitski, and A. Dobson Extravascular lung water in the exercising horse J Appl Physiol, December 1, 2001; 91(6): 2442 - 2450. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Manohar, T. E. Goetz, and A. S. Hassan Nitric oxide synthase inhibition does not affect the exercise-induced arterial hypoxemia in Thoroughbred horses J Appl Physiol, September 1, 2001; 91(3): 1105 - 1112. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. C.W. Hsia Coordinated Adaptation of Oxygen Transport in Cardiopulmonary Disease Circulation, August 21, 2001; 104(8): 963 - 969. [Full Text] [PDF]
|
|
|
|
|
|
M. Manohar, T. E. Goetz, and A. S. Hassan Effect of prior high-intensity exercise on exercise-induced arterial hypoxemia in Thoroughbred horses J Appl Physiol, June 1, 2001; 90(6): 2371 - 2377. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. E. Goetz, M. Manohar, A. S. Hassan, and G. J. Baker Nasal strips do not affect pulmonary gas exchange, anaerobic metabolism, or EIPH in exercising Thoroughbreds J Appl Physiol, June 1, 2001; 90(6): 2378 - 2385. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. B. West Cellular Responses to Mechanical Stress: Invited Review: Pulmonary capillary stress failure J Appl Physiol, December 1, 2000; 89(6): 2483 - 2489. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. Manier, M. Duclos, L. Arsac, J. Moinard, and F. Laurent Distribution of lung density after strenuous, prolonged exercise J Appl Physiol, July 1, 1999; 87(1): 83 - 89. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. H. Erickson, S. L. Bernard, R. W. Glenny, M. R. Fedde, N. L. Polissar, R. J. Basaraba, S. M. Walther, E. M. Gaughan, R. McMurphy, and M. P. Hlastala Effect of furosemide on pulmonary blood flow distribution in resting and exercising horses J Appl Physiol, June 1, 1999; 86(6): 2034 - 2043. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Minetti, L. ArdigO, E Reinach, and F Saibene The relationship between mechanical work and energy expenditure of locomotion in horses J. Exp. Biol., January 9, 1999; 202(17): 2329 - 2338. [Abstract] [PDF]
|
|
|
|
|
|
S. R. Hopkins, C. M. Stary, E. Falor, H. Wagner, P. D. Wagner, and M. D. McKirnan Pulmonary gas exchange during exercise in pigs J Appl Physiol, January 1, 1999; 86(1): 93 - 100. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. E. Taylor, D. S. Kronfeld, P. L. Ferrante, J. A. Wilson, and W. Tiegs Blood-gas measurements adjusted for temperature at three sites during incremental exercise in the horse J Appl Physiol, September 1, 1998; 85(3): 1030 - 1036. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. R. Hopkins, W. M. Bayly, R. F. Slocombe, H. Wagner, and P. D. Wagner Effect of prolonged heavy exercise on pulmonary gas exchange in horses J Appl Physiol, May 1, 1998; 84(5): 1723 - 1730. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. R. Hopkins, R. B. Schoene, W. R. Henderson, R. G. Spragg, and J. B. West Sustained submaximal exercise does not alter the integrity of the lung blood-gas barrier in elite athletes J Appl Physiol, April 1, 1998; 84(4): 1185 - 1189. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Art, D. H. Duvivier, D. Votion, N. Anciaux, S. Vandenput, W. M. Bayly, and P. Lekeux Does an acute COPD crisis modify the cardiorespiratory and ventilatory adjustments to exercise in horses? J Appl Physiol, March 1, 1998; 84(3): 845 - 852. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. F. Speake, C. A. Roberts, and J. S. Gibson Effect of changes in respiratory blood parameters on equine red blood cell K-Cl cotransporter Am J Physiol Cell Physiol, December 1, 1997; 273(6): C1811 - C1818. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. B. West and O. Mathieu-Costello Vulnerability of Pulmonary Capillaries in Heart Disease Circulation, August 1, 1995; 92(3): 622 - 631. [Abstract] [Full Text]
|
|
|
|
|
|
P. McDonough, C. A. Kindig, H. H. Erickson, and D. C. Poole Mechanistic basis for the gas exchange threshold in Thoroughbred horses J Appl Physiol, April 1, 2002; 92(4): 1499 - 1505. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Manohar, T. E. Goetz, S. Humphrey, and T. Depuy H1-receptor antagonist, tripelennamine, does not affect arterial hypoxemia in exercising Thoroughbreds J Appl Physiol, April 1, 2002; 92(4): 1515 - 1523. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
