EFFECTS OF 2-DEOXY-D-GLUCOSE 



393 



consistent in showing an inhibition of the glycolytic pathway by 2-DG. 

 However, the formation of CO2 from glucose is not always depressed. Frid- 

 handler (1959) found that although 2-DG inhibits anaerobic glycolysis 

 in rabbit blastocysts, the rates of respiration and COg formation are not 

 significantly affected. The formation of C^^Og from glucose-1-C^* in human 

 fetal liver is actually increased by 2-DG, but this may be attributed to a 

 partial inhibition of glycolysis (Villee and Loring, 1961). In ascites carci- 

 noma cells 2-DG simultaneously inhibits the glycolysis of glucose and 



X 



INH 



10 



20 



30 



40 



50 



60 



(I) 



70 



mM 



Fig. 2-11. Inhibition of the formation of C^^Oa from glucose-u-C* 



by glucose analogs in rat kidney slices. Glucose was 10 vaM. (From 



Serif and Wick, 1958.) 



increases its oxidation (Christensen et al., 1961), while the disappearance of 

 glucose from the medium is reduced (Fig. 2-12). The increased C^^Oj formed 

 from glucose coupled with the depressed glucose uptake must be taken to 

 mean that the pathway of glucose utilization has been markedly altered, 

 i. e., less glucose is going to lactate and more is being oxidized. One impor- 

 tant factor in such tissues must be the activity of the pentose-P pathway, 

 which is apparently not directly inhibited but is indirectly stimulated by 

 2-DG. The formation of C^^Og from glucose-6-C^* in calf thymus nuclei is 

 inhibited essentially completely by 2-DG (McEwen et al., 1963 b). However, 



