Figure 3. Tunicamycin reduces glucose consumption and glycolysis.

IL-3-dependent Bak^−/−Bax^−/−cells were grown in the medium containing ¹³C-glucose in the presence or absence of 3 µg/ml tunicamycin. The concentrations of metabolites in the medium were determined by SIRM. (A) There was no consumption of the essential amino acid threonine and no significant sources for lactate production other than ¹³C-glucose in IL-3-dependent cells upon 48-hour tunicamycin treatment. Lines are linear regression fits. (B) Consumption of ¹³C-glucose in the medium was decreased in tunicamycin-treated cells. Lines are linear regression fits. The upward curve is fitted to a quadratic function. (C) The fraction of consumed glucose that was converted to secreted lactate was decreased in the presence of tunicamycin. (D) Tunicamycin treatment promoted glutamine consumption from the medium. (E) Lactate production was reduced in tunicamycin-treated cells. The data represent means ± S.D. of three independent experiments. Asterisks indicate P < 0.05 (*), Student’s unpaired t test.