[Hepatic RNA resistance to enzymatic degradation in the process of hepatocarcinogenesis in rats].

During hepatocarcinogenesis, induced in rats with diethylnitrosamine (DENA) and lasting for 6 months, the authors have studied the resistance of hepatic RNA to the degradation by serum RNAs, the resistance being served as a criterion of possible changes in the spacial configuration of polynucleotides. In the precancer period the resistance of RNA molecules (total, cytoplasmic, ribosomal and transfer) is found to considerably increase and then to fall within the range of the studied pH (5.1, 7.6 and 8.5). When the malignancy develops, the RNA resistance to enzymatic cleavage increases again and in most cases exceeds the control level. The comparison of the results obtained with those on the effect of the toxic agent (CCl4) allows a conclusion to be made that the carcinotoxic effect of DENA on the rat liver is accompanied with changes in the spacial configuration of cytoplasmic RNA molecules.