[Tumor and body interrelationships in 14C-thiamine utilization]

Variations in the content of 14C-thiamine, thiamine-dependent enzyme transketolase (TK), and thiamine diphosphate (TDP) in mouse tissues were studied during Ehrlich's ascites tumour growth. The concentration of TDP in the liver of tumour-bearing animals continuously drops during 10 days after inoculation, TDP level in the tumour itself decreases more abruptly by the terminal period of tumour growth (the 10th day). At the same time the tumour demonstrates sharp deficiency of the coenzyme and redundance of apoenzymatic forms of TK. The growing deficiency of thiamine in the tumour favours greater tension of thiamine metabolism and appearance of competitive tumour-host interrelationships that are most pronounced in the presence of hypovitaminosis.