[The biological effects in animals related to the accident at the Chernobyl Atomic Electric Power Station. 2. The state of bone marrow hematopoiesis in rats]. / Biologicheskie éffekty u zhivotnykh v sviazi s avariei na Chernobyl'skoi AES. Soobshchenie 2. Sostoianie kostnomozgovogo krovetvoreniia u krys.

It has been shown that rats born during the first months after the Chernobyl A.P.S. disaster exhibit essential changes in the peripheral blood and bone marrow haemopoiesis throughout the entire lifetime. Rats brought up in Chernobyl from the age of three months on display even more pronounced changes. It is assumed that the changes in the haemopoiesis develop due to the continuous influence of low-level radiation of different quality and are attributed to the effect of the incorporated radionuclides.

[The biological effects in animals in relation to the accident at the Chernobyl Atomic Electric Power Station. 5. Longevity and the carcinogenic effects]. / Biologicheskie éffekty u zhivotnykh v sviazi s avariei na Chernobyl'skoi AES. Soobshchenie 5. Prodolzhitel'nost' zhizni i kantserogennye éffekty.

Remote effects in laboratory animals living in conditions of exposure to a mixture of external and internal radiation resulted from the Chernobyl A.P.S. disaster have been investigated. It has been found that the rate of deaths from non-tumor illnesses grows, the incidence of neoplasms increases and their latency time decreases. The redistribution within the spectrum of benign and malignant tumors and the increase in the multiplicity coefficient have been revealed. It is concluded that chronic exposure of animals to low-level radiation from the radionuclides, resulted from the accident, brings about a much larger number of negative stochastic and nonstochastic remote effects as compared to those expected from the extrapolation of the effects produced by high radiation doses.

[Effect of sodium humate on animals irradiated with lethal doses]. / Vliianie gumata natriia na zhivotnykh, obluchennykh v letal'nykh dozakh.

A therapeutic effect of natrium humate given to experimental mongrel rats exposed to 60Co-gamma-radiation of lethal doses has been studied. A single administration of natrium humate, 5-10 min following irradiation with a dose of 193.5 mC/kg (LD100/30) leads to a 43.3 per cent survival of animals after 60 days; with a dose of 232.2 mC/kg (LD100/8) there is a trend toward the increase in the life span of exposed rats.

[Neutral cytoplasmatic deoxyribonuclease of the rat liver and spleen in carcinogenesis]. / Neitral'naia tsitoplazmaticheskaia dezoksiribonukleaza pecheni i selezenki krys pri kantserogeneze.

The activity of cytoplasmic neutral DNA in the liver and spleen of albino rats is studied when the tumour process develops after fast neutrons irradiation, when tumour is induced by 3,4-benzpyrene and after sarcoma 45 transplantation. It is shown that an increase in the enzymic activity with a further decrease during the process development is observed for all studied types of carcinogenesis in the pretumour period. Changes in the activity of natural inhibitor and the enzyme form bound with the inhibitor were not found (except for one or another index in the spleen of animals with sarcoma 45). The enzyme activation in the pretumour period is considered as a tumour defence response of the organism aimed at elimination of damages in DNA which arise as a result of direct or indirect action of carcinogen.

[Neutral DNAse activity in rat tissues in radiation carcinogenesis]. / Aktivnost' neitral'noi DNKazy v tkaniakh krys pri luchevom kantserogeneze.

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.

[Activity of DNAase I inhibitor in subcellular fractions of rat tissues]. / Aktyvnist' inhibitors DNK-azy I u subklitynnykh fraktsiiakh tkanyn shchuriv

The inhibitory activity in the mitochondrial and postmitochondrial fractions of the liver, spleen and thymus of albino rats was studied with respect to pancreatic DNase I. It is shown to be due to the presence of thermolabile substances of protein nature (natural inhibitors of DNase I) in the subcellular fractions of the organs under study. A higher inhibitory activity is detected in the postmitochondrial fraction of all the tissues under investigation. The lowest inhibitory activity is found in the mitochondrial and postmitochondrial fractions of the liver. The data of a simultaneous study of changes in the activity of tissue DNase and inhibitory activity in the subcellular fractions give reasons to suppose the presence of the nuclease-inhibitory complex in the tissues.