[A comparative evaluation of the efficacy of different methods for the decorporation of plutonium from the respiratory organs]. / Sravnitel'naia otsenka éffektivnosti razlichnykh metodov dekorporatsii organov dykhaniia ot plutoniia.

The behavior of plutonium in the organism and the mechanism of formation of absorbed doses in rats of different age were studied in a comparative aspect. The efficiency of CaDTPA depending on the animal's age and the usage was estimated. Under similar conditions, the efficiency of early single injections of CaDTPA to rat cubs was 2.3 (skeleton) or 3.3 (liver) times lower than that for mature rats. Attempts of modifying the kinetics of low-transportable plutonium-239 by stimulation of pulmonary alveolar macrophages failed.

[Comparative study of hazards of energy plutonium and standard Pu-239 using non stochastic effects]. / Sravnitel'naia opasnost' énergeticheskogo plutoniia i standartnogo 239Pu po nestokhastichesksim éffektom.

In experiment with rats it was found that the "energy" Pu is more toxic than standard 239Pu when entered endotracheally. The comparison was made by the non-stochastic effects. The toxicity in respiratory system and blood system was 1.8 and 1.6 times higher when calculated per 1sGy of absorbed dose and 1.6 and 1.1 times higher when calculated per 1kBg/kg of the amount taken, respectively.

[Modifying effect of tributylphosphate (TBP) and hexachlorbutadien (HCLB) on non-stochastic effects of inhaled Pu-239]. / Modifitsiruiushchee vliianie tributilfosfata (TBF) i geksakhlorbutadiena (GKhBD) na nestokhasticheskie éffecty ot ingaliruemogo 239 Pu.

It has been established in experiments on rats that under combined inhalation exposure to 239Pu along with TBP and HCLB in amounts which may cause the changes in blood and immune systems the enhancing of different non-stochastic effects on the average by two times on a basis of a unit absorbed dose in comparison with isolated nuclide inhalation.

[238Pu body distribution in dogs after intravenous administration and early complexon therapy]. / Raspredelenie 238Pu v organizme sobak posle vnutrivennogo vvedeniia i rannei kompleksonoterapii.

The paper is concerned with the assessment of the level and concentration of 238Pu in different organs and tissues of dogs after iv injection of 238Pu-citrate at the amount of 92.5 kBq.kg-1 and during early complexon therapy. Ninety per cent of Pu detected in the body was shown to be deposited in the skeleton and liver in the ratio 4.5:1. The concentration of 238Pu in per cent to 1 g of tissue in the critical organs (the skeleton, liver, bone marrow) was (28.7--46.9) X 10(-3)%. The concentration of the radionuclide in the organs and tissues regarded as uncritical, was 1-2 orders lower: the endocrine organs--(0.7--7.5) X 10(-3)%, the lymph nodes--(3.8--5.4) X 10(-3)%, the G. I. tract portions--(1.05--1.5) X 10(-3)%, the CNS portions--(0.1--2.0) X 10(-3)%; the kidneys, muscles, heart, spleen and lungs--(0.63--8.8) X 10(-3)%. Early use of octacine or pentacine decreased Pu concentration in all investigated organs and tissues 2 +/- 0.06 times on an average. The efficacy of octacine was no inferior to that of pentacine.

[Distribution of plutonium-239 in the body of dogs 7 days after the intravenous administration of a citrate complex of the metal]. / Raspredelenie plutoniia-239 v organizme sobak cherez 7 sut posle vnutrivennogo vvedeniia tsitratnogo kompleksa metalla.

In experiments with 12 dogs of both sexes it was found that 7 days after intravenous injection of the citrate (2%) complex the concentration of plutonium in the organs and tissues, which are considered noncritical, is lower than in the skeleton by one or two orders of magnitude. No substantial differences were found in plutonium levels in the endocrine glands, (0.7-4.2) X 10(-3%), different parts of the gastrointestinal tract, (0.9-1.7) X 10(-3%), different regional lymph nodes, (2.4-3.8) X 10(-3%), and in different parts of the central nervous system, (0.06-0.19) X 10(-3%) of the total amount of plutonium administered.

[Biological action of 239Pu during intake by inhalation and complexon therapy with Zn or Ca DTPA under experimental conditions]. / Biologicheskoe deistvie 239Pu pri ego ingaliatsionom postuplenii i kompleksonoterapii Zn-ili CaDTPA v éksperimente.

The authors described the effect of substantial amounts of plutonium nitrate administered to rats by inhalation in the presence of Zn- or CaDTPA-complexon therapy for 2 months. A 2-fold decrease of absorbed doses in the lung, a 3-fold decrease in the skeleton and a 4-fold decrease in the liver were shown. The mean life of the treated animals was considerably raised. A significant reduction of the frequency of development of severe pneumosclerosis and an increase in the frequency of lung tumor development were noted. In view of the above, complexon therapy should be necessarily recommended during inhalation of radionuclides in substantial amounts.

[Behavior and biological action of large amounts of 239Pu following intramuscular administration in rats undergoing long-term therapy with Zn- and Ca-DTPA]. / Povedenie i biologicheskoe deistvie bol'shikh kolichestv 239Pu posle vnutrimyshechnogo vvedeniia u krys v usloviiakh dlitel'noi terapii Zn- i Ca-DTPA.

The authors submit the results of the studies of the influence of large amounts of 239Pu, administered to rats via stab wounds, and subsequent treatment there of with clinical doses of Zn- and Ca-DTPA for two months. It is shown that the absorbed doses considerably decrease and the average life of treated rats increases; the incidence of malignant tumors does not change after the treatment with Ca-DTPA.

[Characteristics of natural and pentacin-stimulated urinary excretion of 238Pu and 239Pu]. / Zakonomernosti estestvennoi i stimulirovannoi pentatsinom ékskretsii 238Pu i 239Pu s mochoi.

Experiments on 350 Wistar rats receiving single i. p. doses of 238Pu and 239Pu citrate (pH 6.5) have shown that 0.73-0.84% of the administered nuclides respectively are excreted with urine on the 1st day. By the end of the study (128-260 th day) the excretion value gets stable and equals 0.013-0.018%. Change of the radionuclide excretion natural rate is described in 3 exponential equations. A significantly greater rate of 238Pu excretion was revealed as compared to that of 239Pu excretion over the period of the 2nd-35th day. Intravenous injection of pentacin at a dose of 25 mu mol/kg in one of the above periods (0.5 h, 1; 8; 32; 128 and 256th day) after administration of the nuclides enhances their excretion with urine. On administering the complex after 0.5 h radionuclide excretion was maximum (16.7-20.0%).

[Effect of Na3Zn- and Na3Ca-DTPA on the behavior and biological action of 239Pu on rats]. / Vliianie Na3Zn- i Na3Ca DTPA na povedenie i biologicheskoe deistvie 239Pu u krys.

The effect of a complexon therapy scheme including early (in 1 h) administration of Na3Ca DTPA and subsequent (in 1 day) administration of Na3Zn DTPA or Na3Ca DTPA at a dose of 25 mu Cimol/kg/day by three 2-week courses (5 times a week) with 2-week interruptions was studied in experiments on 541 male rats after intraperitoneal administration of 239Pu citrate complex (95 kBq/kg). The treatment resulted in a 3-fold lessening of the content of 239Pu and absorbed doses in the skeleton, a significant prolongation of the mean survival time (MST) from 452 to 593 days (Na3Zn DTPA) and 643 days (Na3Ca DTPA), and in a decrease of the osteosarcoma incidence from 76.4 to 32.6-41.2%. The ratio of osteosarcomas per 1 Gy retained in rats (0.076-0.083%) did not differ from that in untreated animals (0.067%) and varied within the ranges of established values (0.072-0.119%). The involvement of Na3Zn DTPA in the therapeutic scheme prolongs the MST of rats to a somewhat lesser degree than Na3Ca DTPA. No negative effects of Zn DTPA therapy were revealed.

[Behavior and biological action of 239Pu administered intramuscularly during complexon therapy]. / Povedenie i biologicheskoe deistvie 239Pu pri vnutrimyshechnom vvedenii v usloviiakh kompleksonoterapii.

With intramuscular injection of 239Pu nitrate the radionuclide content of the rat skeleton was higher, and at the site of injection, lower, than with injection of a polymer plutonium. The animals developed osteosarcomas (nitrate greater than polymer), and at the site of trauma, fibrosarcomas (nitrate less than polymer). After a complexon therapy the dose accretion in the skeleton and liver diminished, the life span increased, and the incidence of sarcomas decreased.