Crabtree 1929 Biochem J
|Crabtree HG (1929) Observations on the carbohydrate metabolism of tumours. Biochem J 23:536–45.|
- Estimations of the carbohydrate metabolism of several strains of mouse tumours are recorded. Great deviations from the standard values found for tumours of rat, fowl and a limited series of human tumours were observed in many cases. Wide variations are shown to occur between tumours of different strains, and also between members of the same strain. The most noticeable feature is the number of cases of high respiration, both in its absolute value and also in its relation to the aerobic and anaerobic glycolysis. This respiration is ineffective in checking the aerobic glycolysis, its activity in this direction being, in some cases, less than 10% of that found in the case of working muscle, and in many mammalian tumours. Some factors which might operate in causing these variations are changes in the respiratory quotient, differences of environment during growth, efficiency of blood supply, and the generally higher metabolic rate of the mouse as compared with larger animals.
- A manometric method for the simultaneous measurement of the carbohydrate metabolism and the respiratory quotient is briefly described, based on the fact that the glycolysis effected by tumour tissue is a pure lactic fermentation. The respiratory quotients with one exception were found to be below unity. This would tend to make the actual aerobic glycolysis relatively higher than that usually recorded, since the assumption has hitherto been made that a respiratory quotient of unity would result from the experimental conditions. The results again illustrate the ineffectiveness of respiration in checking glycolysis.
- Xylose is not metabolised by tumour tissue.
- Evidence is brought forward which suggests that the glycolytic activity of tumours exerts a checking effect on their respiration.
- The carbohydrate metabolism of tumours is to some extent influenced by the environment in which they grow. This is demonstrated by the study of two series of Jensen's rat sarcomata, simultaneously transplanted, one series subcutaneously and the other intraperitoneally. The respiration of the subcutaneous growths was, on the average, 50% higher than that of the intraperitoneal growths. The majority of these subcutaneous tumours do not exhibit a positive value for the excess fermentation, which was, until recently, regarded by Warburg as a criterion for the metabolism of tumour tissue. The correlation of these differences with the normal tissue tensions of CO2 and 02 iS difficult. Campbell found the oxygen tension in the abdominal cavity 50% higher than under the skin, the CO2 tensions being approximately the same. The higher respiration found in these two series of tu-mours corresponds to the lower 02 tension in the surrounding tissues, and vice versa. It is obvious that other factors which have not yet been analysed are operative.
The general result of these observations is to emphasise the difficulty of including the wide variations found in the carbohydrate metabolism of tumour tissue in one generalisation. The constant factor is the possession of a high aerobic glycolysis, which, though not specific for tumour tissue, is a source of energy available for uncontrolled ptoliferation.
• Keywords: Crabtree effect
Labels: MiParea: Respiration Pathology: Cancer
Organism: Human, Rat
Preparation: Intact cells
Regulation: Aerobic glycolysis Coupling state: ROUTINE