Nucleic Acids and Their Components in Tumor-Bearing Mice during Growth and Regression of Tumors. ∗

Summary

1. The concentration of ribose nucleic acid (RNA), desoxyribose nucleic acid (DNA), adenine, and guanine of liver, lung, kidney, and spleen of normal C3H mice and those bearing a transplantable mouse lymphosarcoma at different stages of tumor development has been determined. The mice bearing the tumor were divided into 2 groups; one group received desoxypyridoxine on a vit. B₆ deficient diet, while the other received desoxypyridoxine on a diet rich in vit. B6 to counteract the effect of the anti-vitamin. In addition to DNA, RNA, adenine, and guanine, the pyrimidines (uracil, cytosine, and thymine) were also determined in the spleen. 2. The data presented indicate that there is an increase in the nucleic acids and their purine constituents in the liver, kidney, and lung during the growth of the tumor. 3. The nucleic acids reached a higher level in mice receiving desoxypyridoxine on a vit. B₆ sufficient diet than in mice receiving desoxypyridoxine on a vit. B6 deficient diet. 4. Mice receiving desoxypyridoxine on a diet high in vit. B₆ show a maximum value in DNA (which is close to normal) in the spleen on the 17th day of tumor growth which then drops to approximately 20% below normal at 19 days. In mice receiving desoxypyridoxine on a diet deficient in vit. B₆, DNA in the spleen drops quite sharply. At 19 days, this drop is over 70% below normal and this is followed by a similar drop in thymine, cytosine, guanine, and adenine. RNA does not vary to a significant extent in the spleen, and this is also true of uracil. 5. The changes in nucleic acids are followed generally by similar changes in adenine and guanine.