Journal of Applied Physiology, Vol 63, Issue 1 257-261, Copyright © 1987 by American Physiological Society

ARTICLES

Muscle respiratory capacity and VO2 max in identically trained young and old rats

G. D. Cartee and R. P. Farrar

Old rats have a decreased hindlimb muscle respiratory capacity and whole-body maximal O2 consumption (VO2 max). The decline in spontaneous physical activity in old rats might contribute to these age-related changes. The magnitude of the age-related decline is not uniform in all skeletal muscle respiratory enzymes, and the decrease in palmitate oxidation is particularly great. This study was designed to determine if young and old rats subjected to the same exercise-training protocol would attain similar values for VO2 max and several markers of muscle respiratory capacity. Four- and 18-mo-old Fischer 344 rats underwent an identical 6-mo program of treadmill running. After training, both age groups had increased VO2 max above sedentary age-matched controls. However, the old trained rats had a lower VO2 max than identically trained young rats. In contrast to VO2 max, the two trained groups attained similar values for gastrocnemius citrate synthase, cytochrome oxidase, 3-hydroxyacyl-CoA dehydrogenase, palmitate oxidation, and total carnitine concentration. Thus, when the young and old rats performed an identical exercise protocol within the capacity of the old animals, differences in skeletal muscle respiratory capacity were eliminated. The dissimilarity in VO2 max between the identically trained groups was apparently caused by age-related differences in factors other than muscle respiratory capacity.

This article has been cited by other articles:

				E. L. Melanson, W. T. Donahoo, G. K. Grunwald, and R. Schwartz Changes in 24-h substrate oxidation in older and younger men in response to exercise J Appl Physiol, November 1, 2007; 103(5): 1576 - 1582. [Abstract] [Full Text] [PDF]

				H. B Rossiter, R. A Howlett, H. H Holcombe, P. L Entin, H. E Wagner, and P. D Wagner Age is no barrier to muscle structural, biochemical and angiogenic adaptations to training up to 24 months in female rats J. Physiol., June 15, 2005; 565(3): 993 - 1005. [Abstract] [Full Text] [PDF]

				L. G. Koch, C. L. Green, A. D. Lee, J. E. Hornyak, G. T. Cicila, and S. L. Britton Test of the principle of initial value in rat genetic models of exercise capacity Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2005; 288(2): R466 - R472. [Abstract] [Full Text] [PDF]

				I. M. Olfert, J. Balouch, and O. Mathieu-Costello Oxygen Consumption During Maximal Exercise in Fischer 344 x Brown Norway F1 Hybrid Rats J. Gerontol. A Biol. Sci. Med. Sci., August 1, 2004; 59(8): B801 - B808. [Abstract] [Full Text] [PDF]

				T. I. Musch, K. E. Eklund, K. S. Hageman, and D. C. Poole Altered regional blood flow responses to submaximal exercise in older rats J Appl Physiol, January 1, 2004; 96(1): 81 - 88. [Abstract] [Full Text] [PDF]

				R. T. Hepple, J. L. Hagen, D. J. Krause, and C. C. Jackson Aerobic power declines with aging in rat skeletal muscles perfused at matched convective O2 delivery J Appl Physiol, February 1, 2003; 94(2): 744 - 751. [Abstract] [Full Text] [PDF]

				J. Kerner, P. J. Turkaly, P. E. Minkler, and C. L. Hoppel Aging skeletal muscle mitochondria in the rat: decreased uncoupling protein-3 content Am J Physiol Endocrinol Metab, November 1, 2001; 281(5): E1054 - E1062. [Abstract] [Full Text] [PDF]

				R. Barazzoni and K. S. Nair Changes in uncoupling protein-2 and -3 expression in aging rat skeletal muscle, liver, and heart Am J Physiol Endocrinol Metab, March 1, 2001; 280(3): E413 - E419. [Abstract] [Full Text] [PDF]

				M. JEFFERY MADOR, T. J. KUFEL, and L. A. PINEDA Quadriceps and Diaphragmatic Function after Exhaustive Cycle Exercise in the Healthy Elderly Am. J. Respir. Crit. Care Med., November 1, 2000; 162(5): 1760 - 1766. [Abstract] [Full Text]

				L. E. Gosselin Attenuation of force deficit after lengthening contractions in soleus muscle from trained rats J Appl Physiol, April 1, 2000; 88(4): 1254 - 1258. [Abstract] [Full Text] [PDF]

				J. G. Swallow, T. Garland Jr., P. A. Carter, W.-Z. Zhan, and G. C. Sieck Effects of voluntary activity and genetic selection on aerobic capacity in house mice (Mus domesticus) J Appl Physiol, January 1, 1998; 84(1): 69 - 76. [Abstract] [Full Text] [PDF]

				K. L. D. De Angelis, A. R. Oliveira, A. Werner, P. Bock, A. Bello-Klein, T. G. Fernandes, A. A. Bello, and M. C. Irigoyen Exercise Training in Aging : Hemodynamic, Metabolic, and Oxidative Stress Evaluations Hypertension, September 1, 1997; 30(3): 767 - 771. [Abstract] [Full Text]