This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Wu, C. Articles by Bauer, J. M. Search for Related Content PubMed PubMed Citation Articles by Wu, C. Articles by Bauer, J. M.

Catabolism of Xanthine and Uracil in Tumor-bearing Rats^*

( Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan)

The urinary excretion of allantoin and uric acid was greatly increased in rats bearing Walker carcinoma 256. The increase was greater with more advanced tumor growth. A similar increase was also observed in the allantoin concentration of the plasma and liver of these rats. An increase in the RNA and DNA content and a decrease in the RNA/DNA ratio were found in the muscle of the tumor-bearing animals. Liver xanthine oxidase activity was increased in rats bearing Walker 256 and Guerin carcinomas and Novikoff and Morris 3683 hepatomas but was unchanged in rats bearing Jensen sarcoma, Morris 5123, and Morris 3924-A hepatomas, when compared with their respective controls fed ad libitum. Liver uracil reductase activity showed a decrease in rats bearing Morris 5123 and Morris 3924-A hepatomas but no change in rats bearing Walker carcinoma 256 and Novikoff and Morris 3683 hepatomas. These findings indicate that the effect of different tumors on a given enzyme in the host system need not be qualitatively uniform. Finally, unlike the other hepatomas tested, Morris 5123 hepatoma was found to possess xanthine oxidase activity approaching that found in a normal liver.

^* The work was supported in part by a research grant (C1719) from the National Cancer Institute, U.S. Public Health Service.

Received 7/ 7/62.