A note on the action of tannin upon tumour glycolysis.

Considerations dealing with the relation between cell proliferation and carbohydrate metabolism (particularly that of glucose), as well as with certain effects of variation in the water content of growing tissue, have suggested that the intensity of carbohydrate breakdown in proliferating cells is largely dependent upon the degree of hydration of corresponding enzyme proteins, in such a manner that, within limits, an increase in hydration stimulates and a decrease inhibits enzymatic activity (Lasnitzki, 1928, 1945). This assumption is supported by the results of investigations on the influence of hydrating and dehydrating ions upon glycolysis and related processes (see Lasnitzki, 1945). Some further evidence in favour of this assumption, obtained in a different way, is recorded in this note. It was felt desirable to carry out similar investigations with substances whose mode of action differed from that of the electrolytes, although under such conditions research might be confined mainly to the study of the effects of dehydration. The most suitable agents appeared to be represented by the group of vegetable tannins, having regard to the available evidence of their dehydrating power, in low concentrations, upon proteins and other hydrophilic colloids (Kruyt, 1922; Bungenberg de Jong, 1923, 1924), irrespective of the nature of the underlying chemical changes. Experiments on the action of a tannin upon the anaerobic glycolysis of tumour tissue were thus undertaken, and ordinary tannic acid was chosen as the agent to be tested. A transplanted rat tumour, Jensen sarcoma, served as material.