Respiratory inhibitors and uncouplers prevent the aeration-induced increase in mitochondrial anion conductivity.

1. When mitochondria are stirred in air the rate of anion conductivity increases, this effect being enhanced by the addition of respiratory substrate. 2. This effect is reversible if the mitochondria are stored for a period of time under N2. 3. The aeration-induced increase in mitochondrial anion conductivity can also be prevented by the addition of respiratory inhibitors rotenone and antimycin A, as well as by 30 microM-cyanide. 4. A decrease in this aeration-induced anion conductivity can also be observed upon the addition of the uncouplers carbonyl cyanide p-(trifluoromethoxy)phenylhydrazone (2 microM) and 2,4-dinitrophenol (100 microM). 5. Simultaneous measurements of mitochondrial anion conductivity and membrane potential show a relationship between the level of membrane potential and anion conductivity. 6. It is suggested that the level of membrane potential is either directly or indirectly responsible for the level of mitochondrial anion conductivity.