Journal of Applied Physiology, Vol 68, Issue 2 644-649, Copyright © 1990 by American Physiological Society

ARTICLES

31P-NMR spectroscopy and the metabolic properties of different muscle fibers

E. Achten, M. Van Cauteren, R. Willem, R. Luypaert, W. J. Malaisse, G. Van Bosch, G. Delanghe, K. De Meirleir and M. Osteaux
Magnetic Resonance Centre, Vrije Universiteit Brussel, Faculty of Engineering, Belgium.

To study the in vivo recruitment of different fiber types and their metabolic properties, 31P-nuclear magnetic resonance spectroscopy (31P-NMRS) of the human calf muscle was performed in seven normal sedentary subjects. In the exhaustive exercise protocol used, the work load was increased every minute during 5 min. This resulted in a prominent split of the Pi resonance in all subjects, indicating pH compartmentation in the muscles studied. From the chemical shift of the Pi peaks relative to phosphocreatine (PCr) at the end of the exercise, intracellular pH (pHi) averaged 6.92 +/- 0.05 (SD) in compartment 1 and 6.23 +/- 0.15 in compartment 2. The recovery of both Pi resonances after exercise could be followed easily in five of these subjects. The recovery rate of the Pi peak is a good estimate of the oxidative metabolism at the end of the exercise. A monoexponential regression analysis showed that the mean initial recovery rate S0 was 2.49 +/- 0.17%/s in compartment 1 and only 0.87 +/- 0.12%/s in compartment 2, indicating aerobic function three times higher in compartment 1 at the end of exercise. The mean relative ATP fraction dropped significantly (P less than 0.001), from 20.0 +/- 1.0% of the total 31P signal integral before exercise to 14.0 +/- 1.6% at the end of exercise. The simultaneous visualization of two compartments, in good order, one with high pHi and fast recovery and another with low pHi and slow recovery, is rationalized by the different metabolic behavior of type I and II fibers in human calf muscle in response to exhaustive exercise. This study demonstrates that 31P-NMRS is an excellent noninvasive procedure to quantify aerobic metabolism in both fiber types simultaneously.

This article has been cited by other articles:

				B. Pfleiderer, J. Lange, K.-D. Loske, and C. Sunderkotter Metabolic disturbances during short exercises in dermatomyositis revealed by real-time functional 31P magnetic resonance spectroscopy Rheumatology, June 1, 2004; 43(6): 696 - 703. [Abstract] [Full Text] [PDF]

				H. B. Rossiter, S. A. Ward, F. A. Howe, J. M. Kowalchuk, J. R. Griffiths, and B. J. Whipp Dynamics of intramuscular 31P-MRS Pi peak splitting and the slow components of PCr and O2 uptake during exercise J Appl Physiol, December 1, 2002; 93(6): 2059 - 2069. [Abstract] [Full Text] [PDF]

				C. J. Houtman, A. Heerschap, M. J. Zwarts, and D. F. Stegeman pH heterogeneity in tibial anterior muscle during isometric activity studied by 31P-NMR spectroscopy J Appl Physiol, July 1, 2001; 91(1): 191 - 200. [Abstract] [Full Text] [PDF]

				E. Pouliou, S. Nanas, A. Papamichalopoulos, T. Kyprianou, G. Perpati, I. Mavrou, and C. Roussos Prolonged Oxygen Kinetics During Early Recovery From Maximal Exercise in Adult Patients With Cystic Fibrosis Chest, April 1, 2001; 119(4): 1073 - 1078. [Abstract] [Full Text] [PDF]

				D. Meynial-Denis, M. Mignon, L. Foucat, G. Bielicki, A. Ouali, C. Tassy, J.-P. Renou, J. Grizard, and M. Arnal pH Is Regulated Differently by Glucose in Skeletal Muscle from Fed and Starved Rats: A Study Using 31P-NMR Spectroscopy J. Nutr., January 1, 1998; 128(1): 28 - 34. [Abstract] [Full Text]

				R. W. Wiseman and M. J. Kushmerick Creatine Kinase Equilibration Follows Solution Thermodynamics in Skeletal Muscle J. Biol. Chem., May 26, 1995; 270(21): 12428 - 12438. [Abstract] [Full Text] [PDF]