[Quantitative evaluation of the combined effect of external gamma radiation and internal alpha radiation from 239Pu based on biochemical indices of the organs of the rat immune system]. / Kolichestvennaia otsenka sovmestnogo deistviia vneshnego gamma-izlucheniia i inkorporirovannogo al'fa-izlucheniia 239Pu po biokhimicheskim pokazateliam organov immunnoi sistemy krys.

The combined effect of external gamma-radiation (137Cs, 103-26 mC/kg) and incorporated alpha-radiation (239Pu nitrate, 93-9.3 kBq/kg body mass) was estimated by changes in the nucleic acid metabolism and the number of cells in rat thymus, spleen and bone marrow. The data obtained were processed using a model of multiplicate action of the factors which is equivalent, in the case of low effects, to a traditional model of additive effects. The results of the combined action of the two factors may be estimated by the coefficient of the interaction and the coefficient of the enhancement of the effects.

[Aminotransferase and lactate dehydrogenase activity in the blood of dogs exposed to the joint action of external gamma- and internal alpha-radiation]. / Aktivnost' aminotransferaz i laktatdegidrogenazy v syvorotke krovi sobak pri sovmestnom vozdeistvii vneshnego gamma- i inkorporirovannogo al'fa-izluchenii.

After the effect of external gamma-radiation (6.5 to 51.6 mC/kg) and inhaled 239Pu submicron oxide, containing 25% of 241Am, (approximately 7 to 10 kBq/kg) delivered separately and in a combination, activities of alanine-aspartate aminotransferase and lactate dehydrogenase changed in an undulatory manner tending to increase at later times; the change rating was a function of type and level of radiation as well as the time lapsed from the onset of exposure. The combined effect of gamma- and alpha-radiation did not exceed the additive effect of the two factors delivered separately.

[Alkaline phosphatase activity of the blood serum in dogs exposed jointly to external gamma irradiation and alpha radiation]. / Aktivnost' shchelochnoi fosfatazy v syvorotke krovi sobak pri sovmestnom vozdeistvii vneshnego gamma-oblucheniia i al'fa-izlucheniia.

Alkaline phosphatase activity in dog blood serum was studied for two years following separate and combined exposure to gamma radiation (6.45 to 51.6 mC/kg) and inhaled submicron 239Pu oxide, containing 25 per cent of 241Am, in chronically effective amounts (approximately 7-10 kBq/kg). Alkaline phosphatase activity was of an undulatory character, and the significance of changes depended upon the kind and the level of radiation as well as the time lapsed from the start of the exposure. With the combined exposure to gamma and alpha radiation in the doses used, no enhancement of the effect was noted as compared with the action of each factor applied separately.

[Lactate dehydrogenase and alkaline phosphatase activity of the serum and radiation-induced osteosarcoma in rats]. / Aktivnost' laktatdegidrogenazy i shchelochnoi fosfatazy v syvorotke krovi i osteosarkomakh, voznikshikh u krys pri radiatsionnom vozdeistvii.

Alkaline phosphatase (AP) and lactate dehydrogenase (LDG) activities are stained in rat blood serum and osteogenic sarcomas of different histostructure, which developed following a combined exposure of 239Pu (92.5 kBq/kg of body mass) and gamma-irradiation (103.2 mC/kg), as well as following separate exposures to these factors at the same doses. Alkaline phosphatase activities in blood serum and neoplastic bone tissues were found to correlate with the histostructure of osteogenic sarcomas, the distribution and the localization of metastases. Shifts in an isoenzymic spectrum of lactate dehydrogenase in neoplastic bone tissues and blood serum are observed, with a tendency to an increase in the LDG3 and LDG4 and to a decrease in the LDG5 fractions.

[Alkaline phosphatase and transaminase activity in the liver and blood serum of rats in the late periods following combined exposure to external gamma radiation and alpha radiation from plutonium-239]. / Aktivnost' shchelochnoi fosfatazy i transaminaz v pecheni i syvorotke krovi krys v otdalennye sroki posle sochetannogo vozdeistviia vneshnego gamma-izlucheniia i al'fa-izlucheniia plutoniia-239.

A study was made of activity of alkaline phosphatase and alanine- and aspartate aminotransferase in rat liver and blood serum at remote times after external gamma-irradiation combined with internal exposure to 239Pu nitrate delivered in two chronically effective doses. The radionuclide was shown to be mainly responsible for the changes observed in activity of the enzymes under study. The degree to which the changes were manifest depended upon dose of plutonium administered.

[Biochemical changes in rat tissues as affected by the combined action of external gamma-radiation and 239Pu in different doses]. / Biokhimicheskie sdvigi v tkaniakh krys pri sochetannom vozdeistvii vneshnego gamma-izlucheniia i 239Pu v raznykh dozakh.

Under the combined effect of external gamma-radiation (25.8 and 103.2 mC/kg) and 239Pu (18.5 and 92.5 kBq/kg body weight) the changes in the nucleic acids of rat thymus tissues depended upon the intensity of gamma- and alpha-radiation. The damage to the thymus produced by the combined effect was weaker than that of the effect of the two types of radiation delivered separately. In bone tissue, summation of the oppositely directed changes in alkaline phosphatase activity was registered after the effect of gamma-radiation and 239Pu delivered separately.

[Dynamics of nucleic acid metabolism in the bone marrow and liver of rats exposed to the combined action of external gamma radiation and plutonium-239]. / Dinamika obmena nukleinovykh kislot v kostnom mozge i pecheni krys pri sochetannom vozdeistvii vneshnego gamma-oblucheniia i plutoniia-239.

A combined effect of a single exposure to gamma-radiation (103.2 mC/kg) and plutonium-239 (92.5 kBq/kg body weight) caused a decrease in the total number of caryocytes and a change in the nucleic acid metabolism in rat bone marrow. At early times, the changes noted in the bone marrow, as well as in other radiosensitive tissues, were induced by gamma-radiation; at later times (180-360 days), the effect was evidently produced by the incorporated plutonium. In liver tissues, the variation of all the parameters under study was less pronounced.

[Formation of thymine nucleotides in bone marrow of animals of different species]. / Ob obrazovanii timinnukleotidov v kostnom mozge zhivotnykh razlichnykh vidov.

The activity of enzymes of thymidine and thymidylic acid phosphorylation up to thymidine triphosphate and dCMP-desaminase was studied in bone marrow of rats, rabbits and dogs. A soluble fraction of hyaloplasm obtained after bone marrow homogenates centrifugation at 105000xg for an hour at 0-4 degrees C used as a source of the enzymes. It is found that the rate of thymidine and TMP phosphorylation up to TTP by the rat and dog bone marrow extracts is approximately the same, in rabbits this process is slower. The formation of TTP from TMP in animals of all three species is 1.4-2 times as active as in thymidine phosphorylation. The highest activity of dCMP-desaminase is found in the bone marrow cells of dogs, in rabbits and rats it is 1.6 and 2 times as low, respectively.

[DNA synthesis enzymatic activity in the bone marrow of rats of different ages]. / Aktivnost' fermentov sinteza DNK v kostnom mozge krys razlichnogo vozrasta

The activity of DNA synthesis enzymes was studied in bone marrow of rats aging from 1 month to 2.5 years. The activity of enzymes of thymidine and thymidylic acid phosphorylation in the rat bone marrow is determined to be practically constant during the whole period of studies. Activity of gCMP-desaminase and DNA-polymerase has a tendency to a decrease during the life period of rats from one to six-eight months, being constant in the following periods.