Fig. 7. Spontaneous Ca²⁺-regulated ¹⁴C-MeAIB transport is potently and preferentially blocked by riluzole, an anti-glutamatergic drug.

Spontaneous Ca²⁺-dependent ¹⁴C-MeAIB transport (20 µM) is measured (15 min, 37°C) with and without various anti-glutamatergic drugs, following their brief (2 min) pre-incubation at 37°C. Spontaneous transport in Ca²⁺-free Krebs buffer was measured in all independent experiments and is generally less than 15% of Ca²⁺-containing control samples, was not affected by any of the drugs tested, and was subtracted as the negative background control. The IC₅₀ value for riluzole (black circles) and phenytoin (open squares) inhibition of ¹⁴C-MeAIB transport was calculated from dose response curves. Data shown are from a representative experiment, and the experiment was repeated n=4 times.