A one-dimensional (proton and phosphorus) and two-dimensional (proton) in vivo NMR spectroscopic study of reversible global cerebral ischemia.
The suitability of two-dimensional (2D) proton spectroscopy for monitoring, in vivo, the changes in levels of brain metabolites induced by cerebral ischemia was investigated in an experimental model of 30-min reversible ischemia induced by four-vessel occlusion in the rat. The resulting data were compared with those obtained by one-dimensional (1D) proton and phosphorus spectroscopy. Phosphorus spectra obtained during ischemia showed significant drops in levels of phosphocreatine (-73%), beta-ATP (-60%), and intracellular pH (to 6.30) and an increase in inorganic phosphate level (905%). 1D and 2D proton spectra showed decreases in the N-acetylaspartate/creatine-phosphocreatine ratio that were not significantly different [-21% (1D) and -32% (2D)]. Similarly, the increases in lactate/creatine-phosphocreatine ratio were not significantly different [2,546% (1D) and 3,020% (2D)]. 2D spectroscopy also indicated a decrease in aspartate (-66%) and an increase in the inositol-choline derivative (+124%) pools during ischemia and an increase in alanine pool (+516%) during reperfusion. The glutamate-glutamine pool and taurine content did not change significantly during ischemia but decreased during reperfusion. The glucose level transiently decreased (-67%) during ischemia and increased immediately after (+261%). The levels of all the metabolites investigated returned to control values within 175 min after ischemia. 2D spectroscopy seems to be a reliable method of monitoring the changes in levels of cerebral compounds known to be involved in ischemia.
Brulatout
S
S
Laboratoire de Recherches Cérébrovasculaires, CNRS URA 641, Université Paris VII, France.
Méric
P
P
Loubinoux
I
I
Borredon
J
J
Corrèze
J L
JL
Roucher
P
P
Gillet
B
B
Bérenger
G
G
Beloeil
J C
JC
Tiffon
B
B
Mispelter
J
J
Seylaz
J
J
D000818:Animals; D002545:Brain Ischemia / Q000503:physiopathology*; D006859:Hydrogen; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D010759:Phosphorus Isotopes; D016548:Prosencephalon / Q000098:blood supply*; D011522:Protons; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000503:physiopathology*
D010759:Phosphorus Isotopes; D011522:Protons; D006859:Hydrogen