Metabolomics of post-mortem blood: identifying potential markers of post-mortem interval

Death results in changes in some metabolites in body tissues due to lack of circulating oxygen, altered enzymatic reactions, cellular degradation, and cessation of anabolic production of metabolites and macromolecules. Metabolic changes may provide chemical markers to better determine the time since death (post-mortem interval), something that is challenging to establish with current observation-based methodologies. The aim of this research was to carry out a metabolic analysis of blood plasma post-mortem, in order to gain a more complete understanding of the biochemical changes that occur following death. Gas chromatography was used to conduct a survey of post-mortem rat blood. Sixty six metabolites were detected post-mortem. Twenty six of these [18 amino acids, glutathione (GSH), 4-Amino-n-butyric acid (GABA), glyoxylate, oxalate, hydroxyproline, creatinine, α-ketoglutarate and succinate] had increased concentrations post-mortem. The remaining 40 metabolites had concentrations that were not dependant on time. This study demonstrates the range of metabolic changes that occur post-mortem as well as identifying potential markers for estimating post-mortem interval.