| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
University of California, Berkeley 94720; Geriatric Research, Education, and Clinical Center, Palo Alto Veterans Affairs Medical Center, Palo Alto, California 95304; University of Colorado Health Sciences Center, Denver, Colorado 80262; and United States Army Research Institute of Environmental Medicine, Natick, Massachusetts 01760
Received 12 September 1994; accepted in final form 15 February 1996.
Roberts, A. C., G. E. Butterfield, A. Cymerman, J. T. Reeves, E. E. Wolfel, and G. A. Brooks. Acclimatization to 4,300-m altitude decreases reliance on fat as a substrate. J. Appl. Physiol. 81(4): 1762-1771, 1996.
We tested
the hypothesis that exposure to altitude decreases reliance on free
fatty acids (FFA) as substrates and increases dependency on blood
glucose. Therefore, the effects of exercise, hypobaric hypoxia, and
altitude acclimatization on FFA, glycerol and net glucose uptake and
release [ = 2(leg blood flow)(arteriovenous concentration)]
and on fatty acid (FA) consumption by the legs (= 3 × glycerol
release + FFA uptake) were measured. Because sympathetic responses have
been implicated, we utilized nonspecific 
-blockade and observed
responses to exercise, altitude, and altitude acclimatization. We
studied six healthy -blocked men () and five matched controls (C)
during rest and cycle ergometry exercise (88 W) at 49% of sea-level
(SL) peak O2 uptake at the same
absolute power output on acute altitude exposure (A1; barometric pressure = 430 Torr) and after 3 wk of chronic altitude exposure to
4,300 m (A2). During exercise at SL, FA consumption rates increased (P < 0.05). On arrival at 4,300 m,
resting leg FFA uptake and FA consumption rates were not significantly
different from those at SL. However, after acclimatization to altitude,
at rest leg FA consumption decreased to essentially zero in both C and
groups. During exercise at altitude after acclimatization, leg FA
consumption increased significantly, but values were less than at SL or
A1 (P < 0.05), whereas glucose
uptake increased relative to SL values. Furthermore, -blockade
significantly increased glucose uptake relative to control. We conclude
that 1) chronic altitude exposure decreases leg FA consumption during rest and exercise;
2) relative to SL, FFA uptake
decreases while glucose uptake increases during exercise at altitude;
and 3) -blockade potentiates
these effects.
exertion; adaptation; metabolism; free fatty acids; glycerol; lipolysis; glucose; hypoxia
This article has been cited by other articles:
|
|
 |
|
  F. M. E. Franssen, H. P. Sauerwein, E. P. A. Rutten, E. F. M. Wouters, and A. M. W. J. Schols Whole-body resting and exercise-induced lipolysis in sarcopaenic patients with COPD Eur. Respir. J., December 1, 2008; 32(6): 1466 - 1471. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. J. Truijens, F. A. Rodriguez, N. E. Townsend, J. Stray-Gundersen, C. J. Gore, and B. D. Levine The effect of intermittent hypobaric hypoxic exposure and sea level training on submaximal economy in well-trained swimmers and runners J Appl Physiol, February 1, 2008; 104(2): 328 - 337. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Benso, F. Broglio, G. Aimaretti, B. Lucatello, F. Lanfranco, E. Ghigo, and S. Grottoli Endocrine and metabolic responses to extreme altitude and physical exercise in climbers Eur. J. Endocrinol., December 1, 2007; 157(6): 733 - 740. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Neya, T. Enoki, Y. Kumai, T. Sugoh, and T. Kawahara The effects of nightly normobaric hypoxia and high intensity training under intermittent normobaric hypoxia on running economy and hemoglobin mass J Appl Physiol, September 1, 2007; 103(3): 828 - 834. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Roels, C. Thomas, D. J. Bentley, J. Mercier, M. Hayot, and G. Millet Effects of intermittent hypoxic training on amino and fatty acid oxidative combustion in human permeabilized muscle fibers J Appl Physiol, January 1, 2007; 102(1): 79 - 86. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Kevin. A. Jacobs, R. M. Krauss, J. A. Fattor, M. A. Horning, A. L. Friedlander, T. A. Bauer, T. A. Hagobian, E. E. Wolfel, and G. A. Brooks Endurance training has little effect on active muscle free fatty acid, lipoprotein cholesterol, or triglyceride net balances Am J Physiol Endocrinol Metab, September 1, 2006; 291(3): E656 - E665. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. E. Barnholt, A. R. Hoffman, P. B. Rock, S. R. Muza, C. S. Fulco, B. Braun, L. Holloway, R. S. Mazzeo, A. Cymerman, and A. L. Friedlander Endocrine responses to acute and chronic high-altitude exposure (4,300 meters): modulating effects of caloric restriction Am J Physiol Endocrinol Metab, June 1, 2006; 290(6): E1078 - E1088. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. K. Polasek, K. A. Dickson, and R. W. Davis Metabolic indicators in the skeletal muscles of harbor seals (Phoca vitulina) Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2006; 290(6): R1720 - R1727. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. C. F. van Heeswijk, G. J. Vianen, G. E. E. J. M. van den Thillart, and J. Zaagsma Beta-adrenergic control of plasma glucose and free fatty acid levels in the air-breathing African catfish Clarias gariepinus Burchell 1822 J. Exp. Biol., June 15, 2005; 208(12): 2217 - 2225. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Nouette-Gaulain, M. Malgat, C. Rocher, J.-P. Savineau, R. Marthan, J.-P. Mazat, and F. Sztark Time course of differential mitochondrial energy metabolism adaptation to chronic hypoxia in right and left ventricles Cardiovasc Res, April 1, 2005; 66(1): 132 - 140. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. U. Saunders, R. D. Telford, D. B. Pyne, R. B. Cunningham, C. J. Gore, A. G. Hahn, and J. A. Hawley Improved running economy in elite runners after 20 days of simulated moderate-altitude exposure J Appl Physiol, March 1, 2004; 96(3): 931 - 937. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. van Hall, J. A. L. Calbet, H. Sondergaard, and B. Saltin Similar carbohydrate but enhanced lactate utilization during exercise after 9 wk of acclimatization to 5,620 m Am J Physiol Endocrinol Metab, December 1, 2002; 283(6): E1203 - E1213. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. A. Sandoval and K. S. Matt Gender differences in the endocrine and metabolic responses to hypoxic exercise J Appl Physiol, February 1, 2002; 92(2): 504 - 512. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. L. Kennedy, W. C. Stanley, A. R. Panchal, and R. S. Mazzeo Alterations in enzymes involved in fat metabolism after acute and chronic altitude exposure J Appl Physiol, January 1, 2001; 90(1): 17 - 22. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. J. Green, B. Roy, S. Grant, R. Hughson, M. Burnett, C. Otto, A. Pipe, D. McKenzie, and M. Johnson Increases in submaximal cycling efficiency mediated by altitude acclimatization J Appl Physiol, September 1, 2000; 89(3): 1189 - 1197. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Braun, J. T. Mawson, S. R. Muza, S. B. Dominick, G. A. Brooks, M. A. Horning, P. B. Rock, L. G. Moore, R. S. Mazzeo, S. C. Ezeji-Okoye, et al. Women at altitude: carbohydrate utilization during exercise at 4,300 m J Appl Physiol, January 1, 2000; 88(1): 246 - 256. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. B. McClelland, P. W. Hochachka, and J.-M. Weber Effect of high-altitude acclimation on NEFA turnover and lipid utilization during exercise in rats Am J Physiol Endocrinol Metab, December 1, 1999; 277(6): E1095 - E1102. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. D. Reynolds, J. A. Lickteig, P. A. Deuster, M. P. Howard, J. M. Conway, A. Pietersma, J. deStoppelaar, and P. Deurenberg Energy Metabolism Increases and Regional Body Fat Decreases While Regional Muscle Mass Is Spared in Humans Climbing Mt. Everest J. Nutr., July 1, 1999; 129(7): 1307 - 1314. [Abstract] [Full Text]
|
|
|
|
|
|
B. C. Bergman, G. E. Butterfield, E. E. Wolfel, G. A. Casazza, G. D. Lopaschuk, and G. A. Brooks Evaluation of exercise and training on muscle lipid metabolism Am J Physiol Endocrinol Metab, January 1, 1999; 276(1): E106 - E117. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
G. A. Brooks, E. E. Wolfel, G. E. Butterfield, A. Cymerman, A. C. Roberts, R. S. Mazzeo, and J. T. Reeves Poor relationship between arterial [lactate] and leg net release during exercise at 4,300 m altitude Am J Physiol Regulatory Integrative Comp Physiol, October 1, 1998; 275(4): R1192 - R1201. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. E. Wolfel, M. A. Selland, A. Cymerman, G. A. Brooks, G. E. Butterfield, R. S. Mazzeo, R. F. Grover, and J. T. Reeves O2 extraction maintains O2 uptake during submaximal exercise with beta -adrenergic blockade at 4,300 m J Appl Physiol, September 1, 1998; 85(3): 1092 - 1102. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. B. McClelland, P. W. Hochachka, and J.-M. Weber Carbohydrate utilization during exercise after high-altitude acclimation: A new perspective PNAS, August 18, 1998; 95(17): 10288 - 10293. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
