Selected inhibition of aminooxyacetic acid on a high-affinity GABA uptake system in mouse brain homogenates

The kinetic analysis demonstrated 2 distinct uptake systems for GABA in various regions of mice brain. One system showed a realteively high substrate affinity Km=12.6 microM, while the other showed a low affinity Km=110 microM. Aminooxyacetic acid (AOAA), either added to the incubation medium or injected ip, showed inhibitory effects on high affinity GABA uptake system. The inhibition of AOAA seems not to be related to the inhibition of GABA-alpha-ketoglutarate transaminase (GABA-T).