COMPARTMENTATION OF GLUTAMATE METABOLISM IN THE DEVELOPING BRAIN: EXPERIMENTS WITH LABELLED GLUCOSE, ACETATE, PHENYLALANINE, TYROSINE AND PROLINE

Abstract

Abstract —(1) Phenylalanine, proline and presumably tyrosine are precursors of the small glutamate pool in brain. This follows from the finding that with these precursors the specific radioactivity of glutamine is higher than the specific radioactivity of glutamate. (2) Glucose is not as efficient a precursor of glutamate and related amino acids in the brain of 10‐day‐old mice as it is in the adult brain. (3) Acetate, phenylalanine, tyrosine and proline are incorporated to about the same extent in glutamate, aspartate and glutamine in the brains of 10‐day‐old and adult mice. (4) The results suggest that the brain of the immature animal uses substrates other than glucose, relative to glucose better than the brain of adult animals.