Depletion and recovery of ATP levels in V79 cells with exposure to inhibitors of glycolysis and oxidative phosphorylation

Cells of the cultured hamster cell line V79 were labeled with tritiated adenosine and then were incubated for up to 30 minutes in the presence of inhibitors of glycolysis and oxidative phosphorylation. These inhibitors were (1) 5 mM KCN plus 5 mM iodoacetate, (2) 5 mM KCN plus 5 mM KF, and (3) 15 mM KCN plus 15 mM KF. The fate of the tritium label was examined during incubation in the presence of inhibitors and also during subsequent incubation in growth medium in the absence of inhibitors. The tritiated ATP pool was found to decrease in cells incubated in the presence of any of the inhibitor combinations, but only in the presence of 15 mM KCN plus 15 mM KF was this pool decreased below the level of detection. Cells incubated in the presence of KCN-KF combinations returned to a normal tritiated ATP level when incubated in growth medium in the absence of inhibitors, while cells incubated in KCN-iodoacetate retained depletion levels of tritiated ATP. Plating efficiency and trypan blue staining showed that KCN-KF treated cells retained viability, while KCN-iodoacetate treated cells degenerated.

Cells were examined for ability to take up tritiated uridine before, during, and after depletion of ATP by incubation in the pres ence of 15 mM KCN plus 15 mM KF. These cells were found to have a variation in uridine uptake that was directly related to intracellular ATP level. Cells in which the ATP was very low exhibited little or no uridine uptake, while cells in which the ATP level was near normal exhibited normal uridine uptake.