[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.

[The effective and ineffective levels of the joint action of 239Pu and gamma radiation according to the change in the ECG indices of dogs]. / Effektivnye i neéffektivnye urovni sovmestnogo vozdeistviia 239Pu i gamma-izlucheniia po izmeneniiu nekotorykh pokazatelei EKG u sobak.

Effective and ineffective levels of the isolated and combined action of inhaled 239Pu and external gamma radiation on dogs were estimated by some changes in the ECG. Specific share of each factor in the combined effect and the quality coefficient of 239Pu were estimated by two criteria of changes in the ECG. The data were extrapolated to man by the most reliable criterion, that is, the decrease in the ECG voltage indicated by the sum of R I, II, III waves.

[Hemodynamics in dogs during external (60Co) and internal (239Pu) irradiation]. / Gemodinamika u sobak pri vneshnem (60Co) i vnutreniem (239Pu) obluchenii.

The author described an experiment on 34 dogs aged 2 to 4, of both sexes, with the body mass of 14.8-0.6 kg. 8 animals entered into the age control group, the rest of the animals were exposed to single combined irradiation (9 dogs), to isolated gamma-irradiation at a dose of 25.8 mC/kg (7 dogs) and submicron 239Pu oxide irradiation at doses less than 7 kBq/kg (10 dogs). Methods of electrocardiography and tetrapolar chest rheography were also used. The results of the experiment have demonstrated that 239Pu inhalation causes hemodynamic shifts (a decrease in stroke, cardiac and rheographic indices). External gamma-irradiation at the above dose produces no significant effect on hemodynamic indices. Combined exposure to external and internal irradiation contributes to earlier formation of hemodynamic shifts as compared to radionuclide action. Combined and isolated effects of external and internal irradiation result in cardiac rhythm destabilization manifested in increased development of sinus arrhythmia and enhancement of its degree as compared to those in the control group.

[Effect of physical exertion on the status of the heart and central hemodynamics as affected by external (60Co) and internal (239PuO2) irradiation]. / Vliianie fizicheskoi nagruzki na sostoianie serdtsa i tsentral'noi gemodinamiki u sobak pri vozdeistvii vneshnego (60Co) i vnutrennogo (239PuO2) oblucheniia.

Experiments were conducted on mongrel dogs aged 2 to 4 with the body mass of 15.1 +/- 0.9 kg. The animals were exposed to combined and isolated gamma-irradiation at a dose of 51.6 mC/kg and submicron 239PuO2 in the amount not less than 7 kBq/kg. Single circular irradiation was provided from 60Co gamma-sources at a dose rate of 1.03-1.3 mA/kg. 239PuO2 was inhaled 6 days after irradiation. 20 min. running on a treadmill with the speed of 4.7 km/h served as a physical exercise model. The dogs were examined 0.5, 1, 1.5 and 4 yrs. after the initiation of the experiment at rest and within 1 h after physical exercise. Methods of tetrapolar chest rheography and electrocardiography were employed. It was shown that in the combined effect of two radiation factors the rates of increase in the cardiac index were inhibited at the expense of physical exercise influence as compared to those in the isolated radionuclide effect and resulted from less "economical" heart action.

[Changes in hemodynamics and ECG in dogs following whole-body external gamma-irradiation]. / Izmeneniia gemodinamiki i EKG u sobak posle obshchego vneshnego gamma-oblucheniia.

Experiments were made on dogs of both sexes aged 2 to 4 with the body mass of 15.3 +/- +/- 1.1 kg. The animals were exposed to single external whole-body gamma-beam irradiation with 60Co at a dose rate of 1.03-1.3 mA/kg. The exposure dose was 51.6 mC/kg. It was shown that the irradiated dogs developed hemodynamic shifts indicating the formation of conditions first for the overstrain of the left cardiac region (arterial hypertension and a decrease in the vascular coefficient indicating an increase in the precapillary tension of the greater circulation) and then for that of the right cardiac region (an increase in the vascular coefficient, concomitant weakening of the precapillary tension of the greater circulation and an elevated influx of the venous blood to the right cardiac region). According to the ECG results, gamma-beam irradiation at a dose of 51.6 mC/kg resulted in noticeable stabilization of cardiac rhythm as compared to the initial one in the course of one month. Later on the irradiated animals developed more marked tachycardia as compared to the control animals of the same age. In most cases tachycardia was combined with bradycardia. After 3.5-4,5 years 75% of the dogs showed signs of the left ventricular overstrain which 6.5-7 yrs later were supplemented in 50% of the animals by the "P-pulmonale" complex typical of the overstrain of the right atrium. In most dogs the formation of the signs of the overstrain of the left and right cardiac regions over time was accompanied by clear-cut changes in the position of the heart. A significant disorder of myocardial function in the irradiated animals showed evidence for the appearance of the coronary T wave in leads II and III and aVF lead.

[ECG indices in dogs after inhalation of 239Pu]. / Pokazateli EKG u sobak posle ingaliatsii 239Pu.

Dogs of both sexes aged 2 to 4 were subjected to inhalation inoculation with polymer 239Pu or submicron 239PuO2 aerosols in amounts close to acute, subacute and chronically effective ones. ECG was recorded in standard, amplified and single leads (V3). All calculations were done by lead II. Signs of the right heart overburdening were noted in the presence of the P-pulmonale complex, deep S1 wave or cardiac electrical axis of SI-SII-SIII type. Signs of the right heart overburdening were revealed after inhalation of polimer 239Pu (70%). The absence of similar changes in damage caused by 239Pu could be attributed to its fast resorption from the lungs resulting in more moderate lesion of the respiratory organs.

[Life-span of rats as affected by a combination of external (137Cs) and internal (237Np) radiation]. / Prodolzhitel'nost' zhizni krys pri sochetannom vneshnem (137Cs) i vnutrennem (237Np) obluchenii.

A study was made of a change in the mean life of rats exposed to external gamma-radiation (51.6 mC/kg) and 237Np (a polymeric nitrate form) administered intratracheally (0.2-188.0 kBq/kg) delivered separately and in a combination. It was established that the effects of gamma- and alpha-radiation were summated.