Figure 6. Effect of oxidizable mitochondrial substrates on the mitochondrial membrane potential.

A, glands were permeabilized in ICM-citrate. Removal of citrate from the incubation medium was followed by an increase in TMRE fluorescence, indicative of mitochondrial depolarization. TMRE fluorescence decreased to its initial level after readdition of citrate. Addition of FCCP (1 μM) to dissipate Δψ_m at the end of the experiment caused a rapid rise of the signal. B, withdrawal of citrate from the intracellular-like medium resulted in a persistent rise in TMRE fluorescence. Subsequent dissipation of Δψ_m with FCCP (1 μM) further increased the TMRE signal.