Figure 2. Glutamate is secreted into the microenvironment by glioma cells.

(A) Levels of extracellular glutamate were determined in three glioma cell lines, U87, LN229 and U118MG for 4 days. C8161 melanoma cells were used as positive control. Media only with no cells was used as negative control. (B) In parallel MTT assays were performed at the same time to be sure that the released glutamate measured was not due to lysed cells.