Glucose glutamate precursor

Hamberger AC, Chiang GH, Nylen ES, Scheff SW, Cotman CW (1979) Glutamate as a CNS transmitter, 1. Evaluation of glucose and glutamine as precursors for the synthesis of the preferentially released glutamate. Brain Res 768 513-530. 

Figure 4. a, H NMR of [ C] enriched glutamate biosynthesized from a glucose precursor by M. ammoniaphilum, as described in Ref. 14. >4 pulse delay of 2 min was used to avoid erroneous overestimation of the satellites resulting from the shorter T/ due to the dipolar interaction, b, decoupled... 

For example, the study (29) of gluconeogenesls by rat hepatocytes from a [3- C] alanine precursor revealed that the label appeared not only in glucose but also In C-3 and C-2 of aspartate and glutamate. The C-3 C-2 intensity ratios In aspartate was consistently 2 1, whereas the equivalent C-2 C-3 ratio for glutamate was 1 1. The flow of C label Into glutamate and aspartate occurs via a sequence of reactions involving transamination of [3- C] alanine to fom [3- C] pyruvate which enters the mitochondrion and is carboxylated to [3- C] oxaloacetate. [3- C]... 

In this way, the nitrogen from several amino adds can be transferred to aspartate, glutamate or glutamine The ketoacid acceptors may originate from glucose or gluconeogenic precursors. The C-1 atom on formyltetrahydrofolate may arise from serine or methionine. In addition HC07 is required for the carboxylation of 5 -phosphoribosyl-5-aminoimidazole. 

Morjaria B and Voaden J M (1979) The formation of glutamate, aspartate, and GABA m the rat retina, glucose and glutamine as precursors / Newochem 33, 541-551... 

Fig. 3. Glutdimate cycles in the brain. The scheme shows the roles of glutamate in the brain. In the neuron, glutamate may act as a transmitter, precursor for GABA, or in the metabolic pool. An example is shown of how the three pools can be selectively destroyed in neostriatum. Glutamate is formed from glucose through the citric acid (TCA) cycle, from glutamine or 2-oxoglutarate. The latter two are derived from the glial cells.

---