Fig. 6.

The effects of 1 mM DON on intracellular amino acid levels as a function of increasing concentrations of extracellular l-glutamine. Cells were pretreated with DON for 40 min and then transferred for 30 min into medium containing 2, 20, or 200 μM l-glutamine. Intracellular amino acid levels were determined using an HPLC assay. For clarity only Glu and Gln levels are shown. The results are the mean values ± SE of 3 experiments. *P < 0.05; **P < 0.01; ***P < 0.001 vs. value measured with 2 μM extracellular glutamine. ##P < 0.01; ###P < 0.001, t-test, samples without or with DON measured with the same concentrations of extracellular glutamine.