[14C-riboflavin metabolism in mice with Ehrlich's ascitic tumor].

The distribution of 14C-riboflavin in the tissues and elimination of radioactive metabolites with the urine during dynamic development (in 3--5--10 days) of the ascitic Ehrlich's tumour in mice after administration of 10 gamma g per mouse of tagged vitamin in 1--3--24 hr subcutaneously and intragastrically were studied. The development of the neoplastic process was accompanied by a reduced deposition of 14C-riboflavin in the tissues of the macroorganism, an increased elimination of tagged metabolites with the urine, a rising content of the tag in the ascitic fluid. The concentration of the tagged vitamin in the tumour cells remained continuously high in all periods of the test under investigation, its results bearing evidence to an impoverishment of the macroorganism in riboflavial under conditions of the malignant tumour growth.