THE EFFECT OF SOME TRANSPLANTABLE TUMORS ON THE NUCLEIC ACID METABOLISM OF THE HOST TISSUES

Abstract

A study was made of the effect of several transplantable tumors on the incorporation in vivo of formate-C14 and tritiated thymidine into the nucleic acids of the host tissues. The presence of the ascitic or subcutaneous forms of the Ehrlich tumor in mice was found to have little effect on the incorporation of formate-C14 into the nucleic acid purines and thymine of the host liver, spleen, kidney, and lung. Experiments with thymidine-H3 were carried out with mice bearing the Erhlich ascites tumor, using three dose levels of the precursor, 0.014, 0.14 and 1.40 μmoles per mouse. At all levels incorporation into liver DNA of the tumor-bearing mice was greater than in controls, whereas the reverse was true for intestinal mucosa, especially at the lowest dosage. With the higher levels of thymidine-H3, incorporation into the DNA of spleen of the tumor animals was higher than in the controls. Variable results were observed for the other tissues examined. The presence of Novikoff hepatoma in rats had little effect on the uptake of tritiated thymidine by the DNA of the host tissues. The presence of the intramuscular form of Walker carcinosarcoma 256 was accompanied by an increased uptake into the DNA of lung and particularly into the DNA of liver and spleen.