ANAEROBIC GLYCOLYSIS AND FERMENTATIONS 



77 



determined by Simonis and Weichart (1958), and the results again point 

 to a block of 3-PGDH (see accompanying tabulation). The relative accu- 



mulations and depletions here are more in accord with equilibrium condi- 

 tions than in most studies, perhaps because the experimental period is 

 shorter. Glucose is metabolized anaerobically as fast as it enters the yeast 

 cell, since no free intracellular glucose can be detected, but 1 mM lodoace- 

 tate was claimed by Cirillo (1962) to lead to glucose accumulation up to 

 40-55 mM in the cell water, which implies a lack of ATP or a particularly 

 high hexosephosphatase activity. 



Ehrlich ascites carcinoma cells are very sensitive to iodoacetate and at 

 0.025 mM the glycolysis is inhibited around 75% under anaerobic condi- 

 tions (Holzer et al., 1955 b). The accumulation of fructose- 1,6-diP is very 

 marked (see accompanying tabulation). Kvamme (1958 a, b) confirmed the 



accumulation of fructose-l,6-diP in these cells treated with 0.05 mM iodo- 

 acetate, but the magnitude of the effect was generally less. One interesting 

 fact is illustrated in this work: the higher the glucose concentration, the less 

 the effect of iodoacetate on the accumulation of fructose-l,6-diP, since the 

 initial level rises with glucose concentration. Fructose- 1,6-diP under other 

 conditions may fail to accumulate in ascites cells, as in the experiments of 

 Wu and Racker (1959) where no rise of this substance was observed, al- 

 though lactate formation was almost completely blocked. However, the 

 ATP level anaerobically in the presence of 0.1 mM iodoacetate was zero 



