Biochemical considerations in 1H spectroscopy. Glutamate and glutamine; myo-inositol and related metabolites.

Glutamate and glutamine, which can be clearly identified and, in part, quantified in proton spectra of the brain, play important roles in normal and pathological biochemistry. Pathways of glutamate metabolism include transamination, dehydrogenation, deamination and decarboxylation (to GABA). Glutamine is notable in hepatic encephalopathy, but is also a significant metabolic fuel in several other organs and tissues, including neoplasms. Myo-inositol is a 6-carbon alcohol which acquires new interest from its detection and quantitation in 1H spectra. Its role, apart from a biochemical relationship to messenger-inositol polyphosphates, is unclear.