Figure 6.

Distribution of MB among mitochondrial and non-mitochondrial compartments in various energetic conditions of the organelle. Guinea pig mitochondria were incubated in the standard assay medium as was described in the Materials and Methods. Additions were as follows MB (2 µM) at 1 min; PM 5-5 mM at 3 min and FCCP 250 nM at 5 min, and the absorbances at 660 nm were measured. Two minutes after each addition, aliquots were collected, mitochondria were sedimented and the absorbance of the supernatant was determined. Then, O₂ gas was bubbled through all of the supernatant samples for 2 min, and a subsequent reduction step was also carried out by using excess sodium dithionite. Absorbances were also recorded after performing the O₂ and dithionite treatments. Curves represent the average of ten independent experiments ± S.E.M. *, # represent significant differences (p < 0.05) relative to the conditions indicated.