Fig 1. NADH oxidation and Δψ_m are reduced in ND5 mutant cybrids.

NADH oxidation (NADH autofluorescence) and Δψ_m (TMRM fluorescence) were measured concurrently by confocal microscopy. (A) In control (CON) cybrids, inhibition of respiration with cyanide (CN^-) increased NADH autofluorescence, reflecting a decrease in NADH oxidation. Conversely, CN^- had no effect on NADH oxidation in ND5 mutant cybrids or ρ⁰ cells. Stimulation of respiration with the uncoupler FCCP significantly increased NADH oxidation in CON cybrids, induced a small increase in NADH oxidation in ND5 mutant cybrids, but did not change NADH oxidation in ρ⁰ cells. (B) CN^- did not cause any significant change in Δψ_m in CON cybrids, ND5 mutant cybrids or ρ⁰ cells, whereas FCCP collapsed Δψ_m in all cell types. Data is mean ± s.d. n = 3.