92 



Summing up, we can state that aerobic life occurs in a perturbed 

 electromagnetic field and that this perturbation may have a pro- 

 found influence on the course of reactions taking place within this 

 field. If so, then there is a new possible mechanism for drug action 

 which we have to consider: drugs may act also by eliminating, in 

 one way or another, the influence of O2. If this influence of O2 on 

 the riboflavine is an important one, then we can expect that sub- 

 stances which eliminate this influence will interfere with oxida- 

 tive phosphorylation, since riboflavine plays an important role in 

 this process. So when studying uncoupling agents, we will have to 

 look out for changes in the orange phosphorescence which ribo- 

 flavine owes to the presence of O2. We can also turn the argument 

 around and say that if we find that drugs which uncouple oxidative 

 phosphorylation afifect triplet excitations specifically, then this 

 pleads for the assumption that £*, in its triplet form, plays an 

 important role in energy transmissions. If the uncoupler specifi- 

 cally acts on riboflavine, then this will support the hypothesis that 

 riboflavine is involved in oxidative phosphorylation by its triplet 

 excitation. 



IODIDE 



One of the substances which strongly quenches the phos- 

 phorescence of riboflavine is iodide. It quenches completely in 

 10"^, incompletely in 10"* Al concentration. Its action fades out on 

 further dilution. This suggests an action radius of the order of 50 

 A. Accordingly, iodide should inhibit oxidative phosphorylation in 

 small concentrations. This point was tested by M. Middlebrook 

 and the author, who isolated mitochondria from rat liver in the 

 usual way, and measured their oxygen uptake and phosphoryla- 

 tion in the presence of beta hydroxybut)Tate. The chloride in the 

 suspension fluid was replaced to varying degrees by iodide. The 

 P/O ratio varied in the various experiments between 2 and 2.6, 

 the average being 2.2. The results of the experiments are summed 

 up in Fig. 23. As this figure shows, oxidative phosphorylation was 



