Effect of mercurial compounds on potassium binding by mitochondria.

Previous observations (1, 2) have emphasized that potassium is bound to liver mitochondria in a manner that permits exchange with potassium ions in the surrounding fluid but not displacement by sodium ions. This bound electrolyte is not removed by treatment with isotonic sucrose solution. The same picture has been demonstrated in preparations of fragmented mitochondria (2), suggesting it adheres directly to the substance of the mitochondrial membrane. It was noted earlier (2) that exposure of mitochondria to low concentrations of HgClz diminished the amount of bound potassium and produced a stimulation in the rate of the exchange reaction. In the present study this observation has been extended by considering the properties of different types of mercurials and by demonstrating that the effect on the exchange reaction can be reversed with thioglycolate. Studies of this report place major emphasis upon the relationship between the action of the mercurials upon oxidative phosphorylation on the one hand, and upon potassium binding, on the other.