Patterns of Glycolytic Enzymes in Rat Liver and Hepatoma.

19, 20, 24†" 33) of the comparative biochemistry of rodent hepatomas have been made. Interest in such studies has been particularly heightened by the introduction of the â€oeminimal deviation†• lines of hepatoma of the rat developed by Morris et al. (13, 14). These studies indicate that insofar as certain characteristics of morphology, metab olism, and rate of growth are concerned (1, 7, 13, 14, 24, 25, 27†" 33),rat hepatomas exist in gradations from types widely divergent from liver to types approaching normal liver. Of particular interest is the fact that the â€oeminimal deviation†• tumors, as exemplified by the Morris 5123, display a low rate of aerobic and anaerobic glycolysis (1, 11, 27). Elwood et at. (7) pointed out that these tumors have a deficiency in glucokinase activity and, conse quently, a decreased ability to take up and utilize glucose. Extending this observation to a variety of other hepatomas these authors found that glucose utilization varied widely and could be correlated roughly with glucokinase levels in that those tumors which glycolyzed slowly possessed low glucokinase activities and grew slowly, whereas the tumors which glycolyzed rapidly possessed high gluco kinase activity and grew rapidly. Similarly, Weber and Morris (30) observed a correlation between the rate of growth and the levels of certain enzymes in the tumors. These authors found that glucose-6-phosphatase and fructose-i , 6-diphosphatase were generally reduced in tumors, being essentially unmeasurable in the rapidly growing tumors. This paper presents a study of glycolytic enzymes in a variety of hepatomas. The data show that the enzyme 1 This investigation was supported by the Cancer Chemo patterns reflect the glycolytic and growth characteristics of the tumors. The findings of Elwood et at. (7) and Weber and Morris (30) are confirmed, but other relation ships are also observed, the most prominent of which is the increase in the level of pyruvate kinase activity associated with the rapidly growing hepatomas. Maryland to the Rahway Labora tories for biochemical studies. The animals were main tained on a commercial chow diet, and when the tumors had reached sufficient size, the animals were decapitated and exsanguinated. The tumors were rapidly excised, trimmed, and blotted. Aliquots of the tumors were used in the studies of Delvin (4) on mitochondrial enzymes, and other aliquots were removed at this time for measurement of the glycolytic enzyme patterns. These aliquots were frozen and stored in the deep …