62 



A SYMPOSIUM ON RESPIRATORY ENZYMES 



between respiration and glycolysis may be interrupted without im- 

 pairing the reactions proper. 



INHIBITION OF THE PASTEUR EFFECT 



A considerable variety of compounds are able to interrupt the 

 Pasteur eflFect, or the Pasteur reaction, as Warburg (35), after dis- 

 covering the specific action of ethyl carbylamine, first called the 

 phenomenon. Table 7 presents a survey of the agents which have 

 been given the most study and which have proved most effective. 

 Similar effects were found with phenylhydrazine by Dickens (36), 

 with dinitrocresol and dinitrophenol by Dodds and Greville (41), 

 and with HCN on certain plant cells by Genevois (42). 



Table 7.— Aerobic release of glycolysis 



The common effect is the release of aerobic glycolytic action up 

 to an anaerobic level, while respiration remains quantitatively un- 

 changed. In Laser's experiments (37, 38) with carbon monoxide and 

 low oxygen pressure the respiratory quotient was lowered, indicating 

 qualitative changes of respiration. With phenosafranine, however, 

 Dickens (39) found that the respiratory quotient of the brain re- 

 mained unity and the manometric and chemical determinations of 

 lactic acid were in excellent agreement. In this case, at least, it seems 

 very probable that the interruption of the Pasteur reaction occurred 

 without a qualitative change of respiration. 



The action of metal-specific inhibitors has been of great interest. 

 Work in this field has revived discussion of the question whether 

 the effect is dependent on, or independent of, respiratory activity. 

 The old observation that in most tissues cyanide released aerobic 



