Ca2+-dependence of the evoked release from guinea pig cerebral cortex slices of endogenous 14C-labelled amino acids, labelled via D-[U-14C]glucose.
Spontaneous and electrically evoked release of exogenous labelled amino acids and endogenous amino acids labelled from D-[U-14C]glucose were compared in control and Ca2+-free medium using guinea pig cerebral cortex slices. Spontaneous release of all labelled amino acids, except that of endogenous 14C-labelled threonine-serine-glutamine (unseparated) and exogenous [14C]aspartate, was doubled in Ca2+-free medium. The major portion of the electrically evoked release of endogenous [14C]glutamate, [14C]aspartate, gamma-amino[14C]butyrate (14C-labelled GABA) and exogenous 3H-labelled GABA was Ca2+-inpendent. More than half of the evoked release of the other labelled amino acids was Ca2+-independent. As the pattern of Ca2+-dependence of the evoked release concurred with the selectivity of the evoked release for endogenous [14C]-glutamate, [14C]aspartate, and 14C-labelled GABA, it was concluded that these labelled amino acids were probably released from the amino acid 'transmitter pool'.
D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D001224:Aspartic Acid / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D002540:Cerebral Cortex / Q000378:metabolism*; D005071:Evoked Potentials; D005947:Glucose / Q000378:metabolism*; D005971:Glutamates / Q000378:metabolism; D006168:Guinea Pigs; D066298:In Vitro Techniques; D008297:Male; D018377:Neurotransmitter Agents / Q000378:metabolism*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D000596:Amino Acids; D005971:Glutamates; D018377:Neurotransmitter Agents; D001224:Aspartic Acid; D005680:gamma-Aminobutyric Acid; D005947:Glucose; D002118:Calcium