RESUMO
Object of the investigation were effects of elevated radiation background on specific body systems in two generations of rats that had been chronically exposed to radiation in the most badly polluted areas of the Kaluga district and eaten local food. Findings included some compensatory deviations in the white blood count, decrease in karyocytes and increase in chromosomal aberration rate in nucleus-containing cells from the femoral bone marrow in younger animals of several groups, morphologic and histochemical shifts in mucous membrane of the esophagus and the stomach, and morphofunctional changes in neurons and glia of the cerebral cortex. These changes are compensatory-adaptive by nature and indicative of destabilization of homeostasis in experimental animals.
Assuntos
Encéfalo/patologia , Encéfalo/efeitos da radiação , Aberrações Cromossômicas/efeitos da radiação , Citogenética/métodos , Leucócitos/patologia , Leucócitos/efeitos da radiação , Neuroglia/patologia , Neuroglia/efeitos da radiação , Lesões por Radiação/complicações , Neoplasias do Timo/etiologia , Acetilcolinesterase/metabolismo , Acetilcolinesterase/efeitos da radiação , Animais , Encéfalo/enzimologia , Doença Crônica , Feminino , Mucosa Gástrica/enzimologia , Mucosa Gástrica/patologia , Mucosa Gástrica/efeitos da radiação , Homeostase/efeitos da radiação , Masculino , Mitose/efeitos da radiação , Ratos , Neoplasias do Timo/patologia , Fatores de TempoRESUMO
Analytical review of the morphological investigations of cerebral cortex neurons of various animals shortly after exposure to X- and gamma-radiation was made. Considered were data of qualitative and quantitative analyses of dystrophic changes in neurons of the sensorimotor cortex of the large cerebral hemispheres of rats immediately and a long period since X-irradiation. Results of the quantitative analysis of structural disorders in the central nervous system neurons suggest radiation-produced damages early after exposure of animals to relatively low doses. Higher incidence of irreversible changes in neurons of the experimental animals, as compared with intact controls, was stimulated by the doses of no more than 0.25 to 1.0 Gy. The relative number of structural disorders in neurons and percentage of irreversibly impaired cells rose proportionally to the dose growth and further delay of the time of investigation. Possible mechanisms of delayed disorders that led to a massive building-up of the number of dystrophic neurons following 3 to 4 months post irradiation of rats are discussed.
Assuntos
Córtex Cerebral/patologia , Córtex Cerebral/efeitos da radiação , Neurônios/patologia , Neurônios/efeitos da radiação , Animais , Relação Dose-Resposta à Radiação , Distrofias Neuroaxonais/etiologia , Distrofias Neuroaxonais/patologia , Lesões Experimentais por Radiação/complicações , Ratos , Fatores de TempoRESUMO
Dystrophic changes in neurons of the sensorimotor cortex of rat's brain in delayed periods following exposure to small fluxes, i.e. 104 and 105 particles/cm2, of accelerated carbon, fluorine, and oxygen ions with an energy of 300 MeV/nucleon and 137Cs gamma-rays at a dose of 1.0 Gy were quantitatively analyzed. Some structural changes of varying degree including death of a part of neurons were observed; however, most of the cells looked unaltered. Glial elements and small blood vessels also developed a reaction. Dynamics of the morphologic changes was studied. Higher effectiveness of small fluxes of heavy charged particles versus gamma-radiation at a dose of 1.0 Gy and dependence of the depth of structural disorders on linear energy transfer were demonstrated.