Serum and liver xanthine oxidase activity in tumor bearing rats and mice

Liver X.O. activity does not change significantly in tumor bearers although it is known that in this case there is a severe protein deficiency (hypoproteinosis). A decrease in the blood serum X.D. activity was observed in tumor bearing rats but no change occurred in the level of the plasmatic protein. It was suggested that the fall in the blood serum enzyme can be due to factors not correlated with the protein deficiency due to the animals inanition.