Figure 4. Effect of mitochondrial inhibitors on increased OCR in MB231 cells during hypoxia.

At peak OCR, MB231 cells were treated with vehicle alone (ethanol/DMSO; closed circles), or treated sequentially (Inhibitor 1 then Inhibitor 2), with the Complex I inhibitor rotenone (0.5 µM) followed by the complex III inhibitor antimycin A (10 µM) (open squares), or antimycin A (10 µM) followed by rotenone (0.5 µM) (open triangles) at the times indicated by the arrows. Comparison of OCRs approximately 10 min after addition of inhibitor 1 (either Rotenone or Antimycin), and approximately 20 min after the addition of inhibitor 2 (Rotenone+Antimycin, or Antimycin+Rotenone) (B). For comparison, antimycin A (10 µM) was added to MB231 cells maintained under normoxia for 105 min and OCR was determined approximately 10 min after antimycin addition. Values represent means ± SEM, n = 5–10; *p<0.01 compared to vehicle.