Influence of aminooxyacetic acid on the potassium-evoked release of [3H]gamma-aminobutyric acid from slices of rat cerebral cortex.
The release of [3H]GABA from superfused slices of rat cerebral cortex was investigated in the presence and absence of the GABA-transaminase inhibitor aminooxyacetic acid (AOAA). In the latter case, an ion-exchange column chromatographic technique was used to separate [3H]GABA from tritiated metabolites released with it into the superfusate. In the absence of AOAA, omission of Ca2+ from the superfusion medium reduced the release of [3H]GABA evoked by a 30 mM K+ pulse by 81.6%, whereas in comparable experiments carried out in the presence of AOAA omission of Ca2+ reduced the K+-evoked release by only 23.5%. Similar results were obtained when a 50 mM K+ pulse was used, whereupon omission of Ca2+ reduced [3H]GABA release by 78.7% in the absence of AOAA as compared with a reduction of only 47.9% when AOAA was present. It is concluded that the presence of AOAA decreases the Ca2+-dependence of K+-evoked [3H]GABA release in this system.
D000612:4-Aminobutyrate Transaminase / Q000037:antagonists & inhibitors; D000085:Acetates / Q000494:pharmacology*; D000625:Aminooxyacetic Acid / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism*; D002852:Chromatography, Ion Exchange; D066298:In Vitro Techniques; D011188:Potassium / Q000494:pharmacology*; D051381:Rats; D014316:Tritium; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
D000085:Acetates; D014316:Tritium; D000625:Aminooxyacetic Acid; D005680:gamma-Aminobutyric Acid; D000612:4-Aminobutyrate Transaminase; D011188:Potassium; D002118:Calcium