Efflux of amino acid neurotransmitters from rat spinal cord slices. I. Factors influencing the spontaneous efflux of [14C]glycine and 3H-GABA

Robert W P Cutler, John Hammerstad, Linda R. Cornick, Joel E. Murray

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37 Scopus citations


The efflux from nervous tissue of presumptive amino acid transmitters was studied by superfusing rat spinal cord slices preloaded with [14C]glycine and 3H-GABA. The rate of efflux of the amino acids was slower than that of urea and was retarded by superfusion at 4°C. Extracellular glycine exchanged with intracellular [14C]glycine, but did not affect the rates of efflux of labeled GABA, proline, l-lysine, or cycloleucine. The efflux of [14C]glycine was accelerated by extracellular GABA, unaffected by extracellular AIB or proline, and retarded by extracellular l-lysine and l-leucine. Ouabain increased the rate of efflux of [14C]glycine and 3H-GABA, but did not affect [14C]urea efflux. Cyanide stimulated the efflux of [14C]glycine but not 3H-GABA. The rates of efflux of both amino acids were increased in Ca-free medium containing EDTA, unchanged in 30 mM K medium, and decreased in low Na medium. The results indicate that there are mediated transport systems with considerable specificity which regulate the efflux of glycine and GABA across neural membranes.

Original languageEnglish (US)
Pages (from-to)337-355
Number of pages19
JournalBrain Research
Issue number2
StatePublished - Dec 24 1971
Externally publishedYes


ASJC Scopus subject areas

  • Developmental Biology
  • Molecular Biology
  • Clinical Neurology
  • Neuroscience(all)

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