[Neutral DNAse activity in rat tissues in radiation carcinogenesis]

The activity of neutral DNAse and its natural protein inhibitor was determined in the liver, brain and spleen of albino rats with malignant tumours of mammary gland and other organs. The tumours appeared 14-20 months after the irradiation of rats with fast neutrons (0.5-1.0 Gy). It is shown that the activity of DNAse I and its protein inhibitor increases in the liver and brain of tumour-bearing rats, while the enzyme and inhibitor capacity to form the nuclease-inhibitor complex decreases, especially in the liver. It is suggested that the increase in the DNAse activity in the tumour-bearing rats liver is important in the antitumour activity of the organism.