[Hemodynamics in dogs during external (60Co) and internal (239Pu) irradiation].

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.