Sgo 



METABOLISM OF THE CANCER CELL 



MUSCLE 



LIVER 



Fig. 2. Metabolic patterns for pyruvate-2-''*C in various tissues. (Busch, 1955). The upper 

 line represents the total isotope in the whole tissue (total) or the isotope/g of tissue 

 (counts/min/g). The weights for various tissues were, approximately: liver, 8 g; kidney, 

 3 g; spleen, 4 g; testis, 5 g; heart, 1.5 g; brain, 3 g. The shaded areas are percentages 

 of the total isotope in the particular compound at the various time points and are labeled 

 as follows: lactic acid, Lactic; Glutamic acid, GL; alanine, AL; aspartic, ASP; succinic 

 acid, SUCC; and unknowns, U. Maximal recoveries of the isotope in tissues ranged from 



75 to 100 per cent. 



in lactate in the tissues, but was reduced to 3-20% for non-tumor tissues by eight 

 min. In the tumors 50% of the total radioactivity remained in lactate after this 

 same eight minute interval. These interesting findings are further illustrated in 

 Fig. 2 (Busch, 1955). An extension of the studies involved the metabolism of 

 pyruvate-2-''*C in in vitro systems containing slices of Walker 256 carcinoma, 

 Jensen sarcoma, uterine carcinoma, liver, kidney, spleen and brain (Busch et al., 

 1956). The tumor slices incorporated approximately 14% of the ''^C as CO2, 64% 

 into lactate and 21% into amino acids. Addition of glucose to the medium 

 resulted in the follow^ing incorporation : 3%, 92% and 5% into the CO2, lactate and 

 amino acids respectively. The addition of glucose to kidney or liver slices did not 

 significantly alter the metabolic pattern. Of interest, in view of the metabolism 

 of brain tissues was the varying distribution of '"^G in diflferent mediums. In the 

 unsupplemented medium, brain slices transferred 66% of the ^'^C to amino acids. 



