Observation and identification of metabolites emerging during postmortem decomposition of brain tissue by means of in situ 1H-magnetic resonance spectroscopy.
Postmortem decomposition of brain tissue was investigated by (1)H-magnetic resonance spectroscopy (MRS) in a sheep head model and selected human cases. Aiming at the eventual estimation of postmortem intervals in forensic medicine, this study focuses on the characterization and identification of newly observed metabolites. In situ single-voxel (1)H-MRS at 1.5 T was complemented by multidimensional homo- and heteronuclear high-resolution NMR spectroscopy of an extract of sheep brain tissue. The inclusion of spectra of model solutions in the program LC Model confirmed the assignments in situ. The first postmortem phase was characterized mainly by changes in the concentrations of metabolites usually observed in vivo and by the appearance of previously reported decay products. About 3 days postmortem, new metabolites, including free trimethylammonium, propionate, butyrate, and iso-butyrate, started to appear in situ. Since the observed metabolites and the time course is comparable in sheep and human brain tissue, the model system seems to be appropriate.
Ith
Michael
M
Department of Clinical Research (MR Spectroscopy and Methodology), University Bern, Switzerland.
Bigler
Peter
P
Scheurer
Eva
E
Kreis
Roland
R
Hofmann
Lucie
L
Dirnhofer
Richard
R
Boesch
Chris
C
D000818:Animals; D001344:Autopsy; D001921:Brain / Q000378:metabolism*; D002087:Butyrates / Q000378:metabolism*; D006801:Humans; D006859:Hydrogen; D009682:Magnetic Resonance Spectroscopy; D011180:Postmortem Changes; D011422:Propionates / Q000378:metabolism*; D012756:Sheep
D002087:Butyrates; D011422:Propionates; D006859:Hydrogen