Figure 7. Effect of the glutamate transporter inhibitor dl-TBOA on hypoosmotic medium induced amino acid release in the cortex and glutamate transporter reversal in cultured astrocytes.

(a–b) Microdialysis probes implanted on opposite sides of the cortex were perfused with hypoosmotic medium in the presence or absence of 500 µM dl-TBOA, given 20 minutes prior to and during one hour hypoosmotic medium perfusion. The data represent average dialysate levels of glutamate (a), aspartate (b) ±SEM from 4 rats. ** p<0.01 HYPO vs. HYPO+TBOA. (c) DL-TBOA effectively prevented reversal of glutamate transporter in cultured astrocytes. Cultured astrocytes were superfused for one hour with 1 mM ouabain and additionally for 20 min high [KCl] (100 mM) plus ouabain to induce glutamate transporter reversal. 300 µM dl-TBOA was given 10 minutes prior to and during the high [KCl] perfusion in the presence of ouabain. The data are the average values ±SEM for three experiments in each group. ** p<0.01 KCl vs. KCl+TBOA.