AJP - Cell Physiology, Vol 254, Issue 3 C417-C422, Copyright © 1988 by American Physiological Society
Spatial heterogeneity of metabolism in skeletal muscle in vivo studied by 31P-NMR spectroscopy
R. A. Challiss, M. J. Blackledge and G. K. Radda
Department of Biochemistry, University of Oxford, United Kingdom.
Phase-modulated rotating-frame imaging, a localization technique for
phosphorus nuclear magnetic resonance spectroscopy, has been applied to
obtain information on heterogeneity of phosphorus-containing metabolites in
skeletal muscle of the rat in vivo. The distal muscles of the rat hindlimb
have been studied at rest and during steady-state isometric twitch
contraction; the use of a transmitter surface coil and an electrically
isolated, orthogonal receiver Helmholtz coil ensure accurate spatial
assignment (1 mm resolution). At rest, intracellular pH was higher and
PCr/(PCr + Pi) was lower in deeper muscles compared with superficial muscle
of the distal hindlimb. Upon steady-state stimulation, the relatively more
alkaline pH of deep muscle was maintained, whereas greater changes in
PCr/(PCr + Pi) and Pi/ATP occurred in the superficial muscle layer. This
method allows rapid (75 min for each spectral image) acquisition of
quantitative information on metabolic heterogeneity in vivo.
