Effect of NO on the activity of OXPHOS complexes (A and B) and cytochrome c release (C) in APO-S and APO-R Jurkat cells. After treatment with the NO donor GTN (0.2 mmol/L) for 8 hours, 3 × 107 cells were permeabilized with digitonin. Oxygen consumption was measured at 37°C using a Clark type oxygen electrode as described in Materials and Methods. To evaluate cytochromec release, 6 × 107 cells were homogenized on ice and Western blot analysis with anticytochrome c MoAb was performed. (A) Downregulation of OXPHOS complex activity under NO treatment. O2 consumption is expressed as percentage of untreated control. (B) NO-mediated inhibition of complex IV activity. Data are expressed in fmol of consumed O2 per minute per cell. Each bar represents the mean ± standard deviation (SD) of three independent experiments. (C) Time-dependent release of cytochromec into the cytosol in APO-S, but not in APO-R cells. A representative experiment of three is shown.
