ATP contents and condensed configuration of rat liver mitochondria induced by rising ionic strength

Experiments using shifts in ionic strength between 0.15 and 0.8 mol/l revealed that from 0.3 mol/l KCl onward toward higher concentration condensed mitochondria are observed. Parallel with increasing condensation, the ATP contents were found to rise up to 0.6 mol/l KCl. At 0.8 mol/l KCl already destroyed mitochondria were found. Also, at this concentration of KCl, ATP contents did not rise any longer. The SH reagent 2-mercaptopropionylglycine was effective at about physiological ionic strength only. Up to concentrations of 0.6 mol/l KCl H+/O ratios were not different from the controls at physiological ionic strength, but the effect of valinomycin was effectively reduced by high concentrations of KCl. It is suggested that condensation of mitochondrial structure is correlated with increases in ATP content.