Energy rich phosphates in slow and fast human skeletal muscle.
Vandenborne, K., G. Walter, L. Ploutz-Snyder, R. Staron, A. Fry, K. De
Meirleir, G. Dudley, and J. S. Leigh.
Department of Rehabilitation Medicine, University of Pennsylvania,
Philadelphia, Pennsylvania 19104; Department of Radiology - MMRRCC,
University of Pennsylvania, Philadelphia, Pennsylvania 19104; Department of
Sports Medicine, Free University of Brussels, 1090 Brussels, Belgium;
Department of Biological Sciences, Ohio University, Athens, Ohio 45701; and
Muscle Biology Laboratory, Marshall University, Huntington, West Virginia
25702
APStracts 2:0015C, 1995.
We investigated the relationship between energy rich phosphate content and
muscle fiber type composition in human skeletal muscle using a combination of
31P-Nuclear Magnetic Resonance spectroscopy, histochemical and biochemical
analyses of muscle biopsies. Localized 31P-spectra were collected
simultaneously from the predominantly slow-twitch soleus muscle and the mixed
(fast-twitch and slow-twitch) medial and lateral gastrocnemius muscles using
B1 insensitive Hadamard Spectroscopic Imaging (HSI). Biopsy samples were
taken from the soleus and lateral gastrocnemius muscles prior to NMR
investigation and analyzed for fiber type composition and succinic
dehydrogenase activity (SDH). Fiber type composition was determined based on
both myofibrillar actomyosin ATPase activity combined with cross-sectional
area, and myosin heavy chain composition. Localized spectroscopy demonstrated
a significantly (P<0.001) higher Pi/PCr ratio in the soleus muscle
(0.15+/-0.01) compared to the medial (0.12+/-0.01) and lateral (0.10+/-0.0)
gastrocnemius. However, in vitro analysis of muscle biopsies showed only a
moderate relationship between the basal phosphate content and mATPase-based
fiber type composition and SDH activity, respectively.
Received 16 May 1994; accepted in final form 27 October 1994
APS Manuscript Number C0263-4.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1994 The American Physiological Society.
Published in APStracts on 27 February 1995.