On Respiratory Impairment in Cancer Cells 



345 



metric vessels without disintegration. Anaerobically it produces 15 percent of its 

 dry weight of latcic acid per hour, but aerobically it produces no lactic acid at all. 

 Its respiration, in contrast to that of Cancer cells, is high— indeed, nearly three 

 times higher than the respiration of highly malignant, pure Cancer cells. 



Unlike the chorion, the whole embryo itself is unsuitable for such in vitro ex- 

 periments, because it is disintegrated by the motion of the vessels if it is immersed 

 in salt Solutions or even in homologous serum. Yet the important question of 

 lactic acid production by the living embryo can easily be decided by lactic acid 

 determinations in the affluent and effluent blood vessels of an embryo in situ in a 

 pregnant animal. If an embryo produced as much lactic acid as Cancer cells, a very 

 great increase in the effluent vessels would be found. But no increase has been 

 found. 



By these experiments — with chorion in vitro, and with the total embryo in vivo 

 — it has been shown that intact embryonic cells, in contrast to Cancer cells, pro- 

 duce no lactic acid aerobically. 



Table 1 summarizes the average metabolic values obtained in serum with pure 

 Cancer cells of mice and with pure embryonic cells of mice. They constitute the 



Cells 



Qo, 



Qm° 2 



Qm n s 



Ascites Cancer cells 

 Earle's Cancer cells (high malignancy) 

 Earle's Cancer cells (low malignancy) 

 Chorion of young embryos 



Table 1. Average metabolic values obtained in serum with pure Cancer cells of mice and with pure 

 embryonic cells of mice. Qo 2 means cubic millimeters of oxygen consumed, and Qm° 2 and Qm s 2 

 mean cubic millimeters of lactic acid produced aerobically and anaerobically, respectively, per 



milligram (dry weight), per hour. 



main basic facts. Qm N2 = 70 means that the high-malignancy Cancer cells produce 

 anaerobically per hour an amount of lactic acid equal to 29 percent of their dry 

 weight. The respiration, if normal, should be<2o 2 == — 35, whereasOo 2 == — 7 was 

 found. This means that the respiration of the high-malignancy Cancer cells is only 

 one-fifth ofthat of normal growing cells withO>i X2 = = 70, and only two-fifths ofthat 

 of growing chorion of young embryo with a<2M N ~ = 35. 



Obviously, nothing could be less enlightened than the opinion of Weinhouse 

 that the respiration of Cancer cells is as high, or even higher, than the respiration 

 of normal growing cells. "High" and "low" respiration have greatest significance, 

 of course, when compared with fermentation, as has been defined and emphasized 

 many times since 1923, not only by the early use of such specific quotients as 

 2m 02 /So 23 and <2m N2 /2o 23 but in my words of 1924 cited by Weinhouse, "The 

 respiration of the Carcinoma tissue is too small comparison with its glycolytic 

 power." Without such specification, "high" and "low" can become meaningless; 

 thus, the absolute value of respiration of normal connective tissue is very low, and 

 yet it is no Cancer, because the fermentation too is very low. 



