Fig 5. Potassium depletion of Huh-7 cells results in a similar mitochondrial oxygen consumption rate and a moderately decreased extracellular acidification rate.

Huh-7 cells were cultured on XFe96 FluxPak multi-well plates and subject to mitochondrial and glycolytic stress tests using a Seahorse XF analyzer system. (A) Cells were treated with standard (black squares) or K⁺ free (white squares) medium for > 90 min and assessed for oxygen consumption rate (OCR) under baseline conditions (first 4 points), followed by addition of 1 μM oligomycin (Olig), 2 μM FCCP, 0.5 μM Rotenone (Rot), at the times indicated. Similarly, extracellular acidification was measured under baseline conditions followed by addition of 10 mM glucose (Gluc), 1 μM Olig, and 50 mM 2-deoxyglucose (2-DG). Bars are +/- SEM and are frequently smaller than the symbol. No normalization or adjustment of the data was performed. Similar OCR values and similar response to the drugs under K⁺ free medium indicates that mitochondria are functioning properly, whereas reduced ECAR values but similar response to the drugs suggests either impaired glycolysis or reduced proton efflux.