CARBOHYDRATES AND LIPIDS 



883 



TABLE 4 

 (After Warburg - See Weinhouse et al., 1956) 



Cells 



a 



QO2 



^M 





{O 2 consumed) (lactic produced (lactic produced 

 aerobically) anaerobically) 



Ascites cancer cells 



high malignancy 

 Earle's cancer cells 

 low malignancy 



Chorion of young embryos 



cancerous tissues. The real point of contention has been in the interpretation of 

 the underlying causes for these oxidative differences. Weinhouse and others do not 

 accept the concept that this glycolytic activity of tumors does result from a faulty 

 respiration (Weinhouse, 1956). Some of the more recent findings and views will 

 be presented in further detail. 



Since the original methodology and the observations of Warburg dealing with 

 the respiration and glycolysis of embryonic, retinal, normal body and cancerous 

 cells are adequately presented (Warburg, 1930; Greenstein, 1954) reference will 

 be made only to the recent findings in this area. Warburg (see Weinhouse et al., 

 1956) has referred to the findings presented in Table 4 as further proof that the 

 degree of malignancy may be correlated with an increased fermentation and a 

 decrease in respiration. Woods and associates (Woods et al., 1953, 1955) on the 

 basis of their results strongly adhere to the W'arburg concepts. Mice bearing S91 

 melanoma were exposed to increased environmental temperatures (35^^-40°C). 

 Growth of the 35°-40 °C tumor was inhibited by continued exposure to the in- 

 creased temperature. The in vitro anaerobic glycolysis was lowered in slices of the 

 excised tumor. However, insulin restored the Q.^o. *^f slices from heat treated 

 tumors to a level equal to that of slices from the tumors of mice maintained at 

 lower temperatures. 



Certain of the steroid sex hormones also inhibited anaerobic tumor glycolysis 

 and in some instances this inhibition could be reversed by insulin. While many 

 factors are undoubtedly involved, it would appear that the high glycolytic rate 

 of melanoma and other tumors may depend upon the hexokinase phosphorylation 

 system and insulin activity. Factors that tend to disturb glycolytic capacity may 

 be directly involved in malignant transformation as well as in the maintenance 

 of the glycolytic metabolism characteristic of the malignant cell (Burk and Woods, 

 1956). Actually, Warburg (1955) has postulated that carcinogenesis occurs in 

 two stages. An oxygen deficiency may result in irreversible damage to cellular 

 respiration. In the second stage, the cell types that have succeeded in replacing 

 their lost respiratory energy by fermentative energy become predominant. Ron- 

 doni (1955) is of the opinion that cancer formation represents a failure in protein 



Literature p. gig 



