| Abstract: | This study is devoted to the analysis of DNase activity and DNA fragmentation level in liver cells nuclei of rats with transplanted Guerin's carcinoma on irradiation background. Was shown, that in an organism of previously irradiated rat with tumor the dominance of neoplasm development over the consequences of the irradiation is observed on the initial stages of the experiment. The alignment of gamma-irradiation influencing already takes place from the first stages after Guerin's carcinoma transplantation, which is testified by the decrease of DNase activity of liver cells nuclei and the decrease of a degree of nuclear DNA fragmentation. On the stationary stages of tumor growth the general action of the factors causes differences in the parameters of the investigated animal groups. It shows that together with the constant reduced level of DNase activity the processes of DNA fragmentation strengthen and their intensity reaches maximum during this period. The nature of the fragmented DNA accumulation is similar to the irradiated organism on the first days after the radiation factor removal. Thus, the radiation-induced signal in the organism with tumor is leveled under the conditions of active neoplasm growth; nevertheless, the consequents of its operating do not disappear, and only move away in time. |
