The effect of tumor fractions on the uptake of carbon-14-labeled adenine into the deoxyribonucleic acids of mouse tissues.

Kelly and associates (8, 10, 20) have demon strated that phosphorus-32 is incorporated to a greater extent into the liver, kidney, and spleen deoxyribonucleic acid in mice bearing mammary carcinomas than into those of normal control mice. Comparable results were also obtained by those investigators (19) when tumor-bearing mice were given injections of either formate-carbon-14 (C14) or glycine-2-C14. More recently, Kelly and Jones (9) observed that repeated injections of tissue mashes bring about changes in the nucleic acid turnover of spleen and liver in normal animals. Tyner, Heidelberger, and LePage (24) have found that the specific activity of P32 in the deoxyribonucleotides was lower in normal liver than in the liver of rats bearing Flexner-Jobling carcinoma at 12 and 48 hours following administration of the isotope. The specific activity of adenine-C14 and guanine-C14 followed the same trend following ad ministration of glycine-2-C14. The present paper reports observations which establish a stimulation of adenine-8-C14 uptake into the deoxyribonucleic acid (DNA) of various tissues of tumor-bearing mice. In addition, a similar stimulation of adenine uptake was observed when normal mice were given single injections of tumor homogenate.