Ribonucleic Acid Composition of Rat Liver Tumor

Studies on normal tissues have suggested that the ribonucleic acid (RNA) of nuclei, mitochon dna, microsomes, and supernatant fluid isolated from tissue homogenate has a characteristic nu cleotide composition (7, 8, 16), while other data did not support such a view (6). Results obtained in this laboratory revealed, in fact, the occurrence of characteristic ribonucleic acids in rat liver frac tions prepared from sucrose homogenate (13, 15). In the present investigation, the study was ex tended to cell fractions of primary liver tumors in duced by 4-dimethylaminoazobenzene. The re salts indicated that, in liver tumors, the ribonu cleic acids from the different cellular fractions are less heterogeneous than in normal liver.