Potassium-stimulated gamma-aminobutyric acid release from neurons and glia.
Potassium-stimulated [3H]GABA release has been studied with fractions of glial cells, neuronal perikarya and synaptosomes using a superfusion technique. A monotonic increase in the [3H]GABA release was observed when external K+ concentration was raised from 5 to 15 mM. However, there was no further increase in the [3H]GABA release when K+ was raised above 15 mM. The KCl-stimulated release was saturable at the level of 60-100% stimulation. Potassium-stimulated [3H]GABA release from glial cells was unchanged in the absence of calcium while release from synaptosomes and neuronal perikarya demonstrated Ca2+-dependence. The potassium-stimulated [3H]GABA release was enhanced when superfusion was performed in the presence of 10(-5) M ouabain.
D000613:Aminobutyrates / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D009457:Neuroglia / Q000187:drug effects* / Q000378:metabolism; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D010042:Ouabain / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology*; D011817:Rabbits; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D000613:Aminobutyrates; D005680:gamma-Aminobutyric Acid; D010042:Ouabain; D011188:Potassium; D002118:Calcium