Premium
THE INCORPORATION OF DOUBLE‐LABELLED ACETATE INTO GLUTAMATE AND RELATED AMINO ACIDS FROM ADULT MOUSE BRAIN: COMPARTMENTATION OF AMINO ACID METABOLISM IN BRAIN
Author(s) -
Berg C. J.,
Ronda G.
Publication year - 1976
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1976.tb02627.x
Subject(s) - citrate synthase , glutamine , glutamate receptor , glutamate synthase , citric acid cycle , biochemistry , labelling , tricarboxylic acid , metabolism , amino acid , chemistry , glutamic acid , enzyme , glutamine synthetase , receptor
– We have determined the incorporation of [ 3 H]‐, [1‐ 14 C]‐ and [2‐ 14 C]acetate into glutamate, glutamine and aspartate of the adult mouse brain. All these three acetates were incorporated more extensively into glutamine than into glutamate. This has been reported by several authors for each of these labelled acetates in separate experiments. It was shown that [ 3 H, 2‐ 14 C]acetate can be used to obtain an acetate labelling ratio analogous to the previously used [2‐ 14 C]acetate/[1‐ 14 C]acetate labelling ratio. From these acetate labelling ratios of glutamine and glutamate conclusions can be deduced about the dynamic relationship of these amino acids with each other and with the tricarboxylic acid cycle. A fairly large isotope effect between acetate and glutamate was observed. As this isotope effect is very likely caused by the citrate synthase reaction, it can be argued that citrate synthase involved in the conversion of labelled acetate into glutamate is far out of equilibrium in vivo. Comparing our data with literature data, the possibility can be suggested that citrate synthase in the acetate metabolizing compartment is in situ kinetically distinct from citrate synthase in other compartments of the brain.