P-31 magnetic resonance spectroscopy in polymyositis and dermatomyositis. Altered energy utilization during exercise.
OBJECTIVE
To explore alterations in energy utilization as a potential etiology for weakness in polymyositis and dermatomyositis (PM/DM).


METHODS
P-31 magnetic resonance spectroscopy studies were performed in patients with acute and treated PM/DM and in normal controls, at rest and with exercise.


RESULTS
Patients with acute and treated PM/DM showed increased ratios of inorganic phosphate to phosphocreatine (PCr) during exercise, with loss of ATP disproportional to loss of PCr.


CONCLUSIONS
This study demonstrates changes in energy utilization in PM/DM, thus supporting the notion of a metabolic etiology for the weakness associated with these diseases.
Newman
E D
ED
Department of Rheumatology, Geisinger Medical Center, Danville, Pennsylvania 17822.
Kurland
R J
RJ
D000255:Adenosine Triphosphate / Q000378:metabolism; D003882:Dermatomyositis / Q000378:metabolism*; D004734:Energy Metabolism / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D009132:Muscles / Q000378:metabolism; D009220:Myositis / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism; D010725:Phosphocreatine / Q000378:metabolism; D010758:Phosphorus
D010710:Phosphates; D010725:Phosphocreatine; D010758:Phosphorus; D000255:Adenosine Triphosphate