Quantitative Analysis Of Cerebral Metabolites In Mice By In Vivo H-1-Mrs And Comparison Of Detection Results Of Tissue Extracts Obtained By H-1-Nmr And Uhpcl-Ms/Ms

In vivo proton magnetic resonance spectroscopy (H-1-MRS) can be used to measure regional concentration of multiple brain metabolites simultaneously and non-invasively. The technique has been widely used in the clinical diagnosis and basic researches on neurological/psychiatry diseases. In this study, the concentrations of five cerebral metabolites, namely N-acetyl aspartate (NAA), glutamate (Glu), glutamine (Gln), taurine (Tau) and glutathione (GSH) in two brain regions (i.e., striatum and medial prefrontal cortex) of 12-months old mice were measured by in vivo H-1-MRS using water signal as the internal standard. The detection results were then compared with those obtained by liquid. state H-1-NMR and ultrahigh performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). The results demonstrated that the NAA, Glu and Tau concentrations measured by the three techniques had no statistically significant differences among each other, suggesting that the results of in vivo H-1-MRS analyses were at least as reliably and accurate as those obtained by H-1-NMR and UHPLC-MS/MS. The absolute concentrations of Gln and GSH measured by UHPLC-MS/MS were significantly higher or lower, relative to those measured with magnetic resonance techniques. Such discrepancies might have originated from the systematic errors presented in the UHPLC-MS/MS measurements of Gln and GSH. The results demonstrated the feasibility of combined or complementary use of in vivo H-1-MRS and ex vivo measurements for metabolite profiling in the brain.