[Level of thiamine diphosphate in the liver of tumor-bearing animals kept on a diet including an excessive amount of vitamin B 1].

In mice bearing solid Ehrlich's carcinoma, food consumption did not differ from that in intact animals throughout the whole experiment. In mice with Ehrlich's ascites carcinoma and in rats bearing Walker's carcinosarcoma 256, the daily feed consumption decreased 2-fold by the terminal period of tumor development. In rats, the amount of vitamin B1, calculated per unit of the feed consumed, exceeded the daily requirements of vitamin B1. The content of thiamine diphosphate in the liver of tumor-bearing animals was 35% as reduced whatever the method of inoculation and site of tumor development (under the skin or inside the abdominal cavity). In rats with Walker's carcinosarcoma 256, transketolase activity was 17% as lowered (P less than 0.01). In mice with Ehrlich's carcinoma, the activity of the enzyme was 21% as decreased (P less than 0.01; an ascitic variety) or 17% as decreased (P less than 0.01; subcutaneously inoculated tumor).