Alloxanized Wistar Rats

The high rate of glycolysis in cancerous tissues, first described by Con in vivo (6) and by Warburg in vitro (@2),suggests that a considerable part of the energy supply for the neoplastic process is derived from the “anaerobic―phase of carbo hydrate catabolism. The low glycogen content characterizing a number of tumors (8—11, 13, I 7) may also indicate that the substrate for this process is preferentially glucose. The accentuated rate of glycolysis has formed the basis of at tempts, a number of them successful, to arrest or retard tumor growth in vivo by glycolytic blocking agents such as glyceraldehyde (14, 15, 18), fluoride, and iodoacetate (1, @, 4, @1). A some what different approach to this problem has been the investigation of both the induction and growth of tumors in the alloxan-diabetic rat or mouse, the underlying rationale to this approach being that the high level of extracellular glucose, or the disturbance in carbohydrate and/or pro tein metabolism, may impose metabolic restric tions on neoplastic development (3, 5, 7, 12, 19). In the present study on a rapid-growing trans plantable hepatoma (Novikoff), evidence has been obtained of a marked inhibition of tumor development in the alloxanized rat. A significant reduction in hyperglycemia was observed in the alloxanized animals given injections of the tumor material. On the other hand, the administration of alloxan to rats bearing the hepatoma trans plants was followed by regression or disappear ance of the tumor.