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RELEASE OF [ 3 H]GABA FROM RAT CORTICAL SLICES: NEURONAL VS GLIAL ORIGIN 1
Author(s) -
Hammerstad J. P.,
Lyte C. R.
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.tb12260.x
Subject(s) - biophysics , alanine , chemistry , amino acid , biochemistry , neuroscience , biology
— The effect of L‐2,4 diaminobutyric acid (DABA) and β‐alanine on the K + stimulated release of [ 3 H]GABA was examined using a continuous superfusion system in which a carrier mediated exchange diffusion could be demonstrated between [ 3 H]GABA in preloaded rat cortical slices and unlabeled DABA and β‐alanine in the superfusion medium. These structurally related amino acids were chosen to investigate the source of releasable [ 3 H]GABA because of evidence suggesting they may have differing affinities for the GABA carrier transport system that are specific for neurons and glia, DABA having a greater affinity for the neuronal GABA system and β‐alanine for the glial. Five millimolars‐DABA in the superfusion medium nearly abolished the K + stimulated release of [ 3 H]GABA whereas β‐alanine had little effect. The results and conclusions are discussed in terms of a postulated carrier mediated exchange of unlabeled DABA with a specific neuronal pool of [ 3 H]GABA interfering with the K + stimulated release of the radiolabeled GABA. The results provide indirect evidence in favor of a neuronal pool as the source of releasable [ 3 H]GABA in this system.