[Effect of creatine phosphate synthesis on the membrane potential of mitochondria]

The method of the penetrating ions allows to observe the creatine phosphokinase function of heart mitochondria in steady state conditions. The addition of ADP to respiring mitochondria decreases the membrane potential in the course of the ATP synthesis. The subsequent addition of creatine decreases the membrane potential for a long period of time because of ADP formation in creatine phosphokinase reaction. It was shown in the experiments with maintainance of the constant concentration of ADP or ATP in the medium that the ADP concentration in the medium acts mainly on the membrane potential during the creatine phosphate synthesis. There is no effect of creatine on the membrane potential of liver mitochondria which have no creatine phosphokinase.