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.

Abstract

<p>(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.</p