Phosphorus-31 magnetic resonance spectroscopy studies of pig spinal cord injury. Myelin changes, intracellular pH, and bioenergetics.
OBJECTIVE
Phosphorus-31 (31P) nuclear magnetic resonance (NMR) spectroscopy was used to monitor changes in phosphocreatine (PCr), adenosine triphosphate (ATP), inorganic phosphate (Pi), intracellular pH (pHi), and free magnesium in the in vivo pig spinal cord after injury.


METHODS
Phosphorus-31 NMR spectra were acquired from healthy (n = 4) and injured pig spinal cords (n = 8) under in vivo conditions using a 4.7-tesla spectrometer. Spinal cords were injured by dropping a 20-g weight from 20 cm onto the surgically exposed cord surface.


RESULTS
In vivo spectra of injured cords revealed a reduction in ATP, PCr, pHi, and an increase in Pi. In addition, a broad resonance that is likely to arise from myelin phospholipids was reduced significantly after injury.


CONCLUSIONS
Phosphorus-31 NMR can be used to follow in vivo changes in high energy phosphates after injury and may have the potential to follow changes in myelin structure. This technique may prove important in the study of myelin breakdown after secondary, nonreversible spinal cord injury. Changes in high energy phosphates and pHi did not seem to parallel these putative changes in myelin structure.
Akino
M
M
Department of Neurosurgery, University of Hokkaido, Japan.
O'Donnell
J M
JM
Robitaille
P M
PM
Stokes
B T
BT
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D004734:Energy Metabolism; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D009186:Myelin Sheath / Q000378:metabolism; D010725:Phosphocreatine / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism; D013116:Spinal Cord / Q000378:metabolism*; D013119:Spinal Cord Injuries / Q000378:metabolism*; D013552:Swine
D010743:Phospholipids; D010725:Phosphocreatine; D000255:Adenosine Triphosphate