title: In vitro 31P-magnetic resonance spectroscopy of muscle extracts in malignant hyperthermia-susceptible patients.
abstract: BACKGROUND
  It was recently suggested that malignant hyperthermia-susceptible (MHS) patients could have an elevated peak of phosphodiesters in leg muscles using in vivo phosphorus magnetic resonance spectroscopy. In the current study, analysis of the phosphodiesters of muscle extracts of MHS and malignant hyperthermia-negative patients was performed using in vitro phosphorus magnetic resonance spectroscopy to chemically identify and to compare the muscle concentrations of water-soluble compounds between the two groups with respect to the muscle fiber type composition.
  
  
  METHODS
  Perchloric acid extracts of the vastus medialis muscle of seven MHS patients and ten malignant hyperthermia-negative patients on the basis of the European malignant hyperthermia contracture test were subjected to in vitro phosphorus magnetic resonance spectroscopy carried out at 9.4 T. In addition, chemical identification of the phosphodiester region and histologic examination of the muscle specimens were performed.
  
  
  RESULTS
  The peak in the phosphodiester region was assigned to glycerophosphorylcholine. Muscle perchloric acid extracts of MHS patients had a significantly (P < 0.05) higher glycerophosphorylcholine to the sum of phosphocreatine and inorganic phosphate (glycerophosphorylcholine/ [phosphocreatine +inorganic phosphate]) value than those of malignant hyperthermia-negative patients. Neither a difference in the fiber type composition between the two groups nor any specific myopathy were found.
  
  
  CONCLUSIONS
  In the absence of histologic differences between muscle specimens of MHS and malignant hyperthermia-negative patients, these results could suggest that glycerophosphorylcholine could be a marker of an impairment in the phospholipid metabolism in the skeletal muscle of MHS patients.
authors.affiliation: INSERM, University of Grenoble School of Medicine, France.
authors.forename: J F
authors.initials: JF
authors.lastname: Payen
authors.forename: N
authors.initials: N
authors.lastname: Fouilhé
authors.forename: E
authors.initials: E
authors.lastname: Sam-Lai
authors.forename: C
authors.initials: C
authors.lastname: Rémy
authors.forename: R
authors.initials: R
authors.lastname: Dupeyre
authors.forename: P
authors.initials: P
authors.lastname: Mézin
authors.forename: J
authors.initials: J
authors.lastname: Halsall
authors.forename: P
authors.initials: P
authors.lastname: Stieglitz
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005997:Glycerylphosphorylcholine / Q000032:analysis; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008305:Malignant Hyperthermia / Q000378:metabolism*; D008563:Membrane Lipids / Q000378:metabolism; D008875:Middle Aged; D009132:Muscles / Q000378:metabolism*; D010725:Phosphocreatine / Q000032:analysis; D010743:Phospholipids / Q000378:metabolism*
chemical_list: D008563:Membrane Lipids; D010743:Phospholipids; D010725:Phosphocreatine; D005997:Glycerylphosphorylcholine