QUANTITATIVE H-1 AND P-31 MRS OF PCA EXTRACTS OF POSTMORTEM ALZHEIMERS-DISEASE BRAIN

Several previous studies have shown metabolic abnormalities in perchlo ric acid extracts of postmortem Alzheimer's disease (AD) brain by both proton (H-1) and phosphorus-31 (P-31) magnetic resonance spectroscopy (MRS). In all of these studies the results were expressed in relative terms, in units of mol percent. The results of this study, expressed in the absolute units of mu mol/g wet weight, verify the previous H-1 and P-31 MRS studies. Absolute increases were found for myo-inositol, aspartate, L-glutamate, alanine, phosphocholine, and the phosphodieste rs,. Absolute decreases were found for phosphoethanolamine and N-acety l-l-aspartate. Many of these changes also were observed in non-AD deme ntia brain extracts, bur changes in myo-inositol, inositol-1-phosphate , aspartate, and L-glutamate appeared to be more specific for AD in ex tracts of many brain areas. These results suggest that compounds relat ed to membrane degradation and excitatory neurotransmission increase i n Alzheimer's disease while compounds related to neuronal integrity an d inhibitory neurotransmission are decreased.