Journal of Applied Physiology, Vol 71, Issue 3 961-969, Copyright © 1991 by American Physiological Society

ARTICLES

Absence of exercise-induced MRI enhancement of skeletal muscle in McArdle's disease

J. L. Fleckenstein, R. G. Haller, S. F. Lewis, B. T. Archer, B. R. Barker, J. Payne, R. W. Parkey and R. M. Peshock
Department of Radiology, University of Texas, Southwestern Medical Center, Dallas 75235.

To assess the role of glycogenolysis in mediating exercise-induced increases in muscle water as monitored by changes in muscle proton relaxation times on magnetic resonance imaging (MRI) and cross-sectional area (CSA), five patients with myophosphorylase deficiency (MPD) were compared with seven controls. Absolute and relative work loads were matched during ischemic handgrip and graded cycling, respectively. Relaxation times of active muscle did not increase after handgrip in MPD (T1: 1 +/- 14%, P greater than 0.1; T2: 4 +/- 4%, P greater than 0.1) but did in controls (T1: 59 +/- 30%, P less than 0.005; T2: 26 +/- 9%, P less than 0.005). The volume of exercised muscles, estimated by CSA, increased in both groups after handgrip (controls: 13.8 +/- 3.5%, n = 7, P less than 0.0001; MPD: 7.5 +/- 1.5%, n = 4, P less than 0.005), but the change was greater in controls (P less than 0.02). Ischemic handgrip in controls resulted in a large increase in finger flexor signal intensity (SI) on short tau-inversion recovery images (25 +/- 7%, n = 3; P less than 0.005 compared with preexercise) and a further increase with subsequent reflow (43 +/- 11%, n = 3; P less than 0.001 compared with rest); in MPD, SI did not increase. The ratio of active to inactive muscle SI did not increase from rest to maximal cycle exercise in MPD (0 +/- 20%, n = 2, P greater than 0.1) but did in normals (73 +/- 36%, n = 3; P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

This article has been cited by other articles:

				B. M. Damon and J. C. Gore Physiological basis of muscle functional MRI: predictions using a computer model J Appl Physiol, January 1, 2005; 98(1): 264 - 273. [Abstract] [Full Text] [PDF]

				B. M. Damon, D. M. Wigmore, Z. Ding, J. C. Gore, and J. A. Kent-Braun Cluster analysis of muscle functional MRI data J Appl Physiol, September 1, 2003; 95(3): 1287 - 1296. [Abstract] [Full Text] [PDF]

				L. L. Ploutz-Snyder, E. L. Yackel-Giamis, A. E. Rosenbaum, and M. Formikell Use of Muscle Functional Magnetic Resonance Imaging With Older Individuals J. Gerontol. A Biol. Sci. Med. Sci., October 1, 2000; 55(10): 504B - 511. [Abstract] [Full Text]

				G. Saab, R. T. Thompson, and G. D. Marsh Effects of exercise on muscle transverse relaxation determined by MR imaging and in vivo relaxometry J Appl Physiol, January 1, 2000; 88(1): 226 - 233. [Abstract] [Full Text] [PDF]

				B. M. Prior, J. M. Foley, R. C. Jayaraman, and R. A. Meyer Pixel T2 distribution in functional magnetic resonance images of muscle J Appl Physiol, December 1, 1999; 87(6): 2107 - 2114. [Abstract] [Full Text] [PDF]

				T. B. Price and J. C. Gore Effect of muscle glycogen content on exercise-induced changes in muscle T2 times J Appl Physiol, April 1, 1998; 84(4): 1178 - 1184. [Abstract] [Full Text] [PDF]

				M. A. Sloniger, K. J. Cureton, B. M. Prior, and E. M. Evans Lower extremity muscle activation during horizontal and uphill running J Appl Physiol, December 1, 1997; 83(6): 2073 - 2079. [Abstract] [Full Text] [PDF]

				M. A. Sloniger, K. J. Cureton, B. M. Prior, and E. M. Evans Anaerobic capacity and muscle activation during horizontal and uphill running J Appl Physiol, July 1, 1997; 83(1): 262 - 269. [Abstract] [Full Text] [PDF]