58 A SYMPOSIUM ON RESPIRATORY ENZYMES 



out in an earlier paper (23), which through environmental conditions, 

 such as insuflBcient circulation, are forced to rely partly on a supply 

 of anaerobic energy (cf. 20). Recent measurements by Philip (24) 

 on respiration of the early developmental stages of the chick embryo 

 give evidence that this must be the case. This corroborates our earlier 

 findings based on less conclusive experimental data. Philip's remarks 

 may be quoted here: "The study of the early blastomere," he says. 



Table 6.— Metabolism of tumor tissue 



^°^'^'' Refer- 



Tumor Qo, Q^'g Q^'g CQ. tion "®^^^ 



^ , ence 



per cent 



Flexner-Jobling carcinoma, 



rat -15 23 23 54 



- 7 16 24 3 33 

 Adenocarcinoma, human 



male - 9 16 29 4.2 42 75 



- 1.2 5 12 15 58 

 9 22 M 59 



Jensen sarcoma -14 16 34 3.9 53 39 



Walker sarcoma 256 ... -22 25 46 2.9 46 39 



The average R.Q. for all the tissues was 0.85. 



"has revealed that oxygen diffusion limits the oxygen consumption 

 in oxygen tensions of the air. This indicates that the early blastomere 

 may actually be in a state of partial anaerobiosis." And later in the 

 same discussion: "The considerations presented suggest that some 

 of the energy used during early periods of growth can be pro- 

 vided to the embryo by anaerobic processes. This condition is prob- 

 ably associated with the rapidly increasing size of the embryo 

 during early periods before the circulation system can function as 

 an adequate oxygenating mechanism." The relatively poor vascu- 

 larization of most tumors is evidence that the last statement holds 

 likewise for malignant growth. We are led then to the conclusion 

 that the high capacity of the anaerobic metabolism present in normal 

 and in malignant growing tissues should be attributed to their partly 

 anaerobic state of life rather than to an unlikely special growth 

 function of glycolysis. 



A curious phenomenon of hyperfunction of the Pasteur effect is 

 observed in human beings at high altitudes (25). The relatively high 

 lactic acid level of the blood which would be expected at low 

 oxygen pressure is observed only before adaptation occurs (25). 



