Assuntos
Butadienos/administração & dosagem , Butadienos/efeitos adversos , Fungicidas Industriais/administração & dosagem , Neoplasias Experimentais/induzido quimicamente , Neoplasias Experimentais/etiologia , Neoplasias Induzidas por Radiação/etiologia , Organofosfatos/administração & dosagem , Organofosfatos/efeitos adversos , Plutônio/administração & dosagem , Plutônio/efeitos adversos , Protetores contra Radiação/administração & dosagem , Protetores contra Radiação/efeitos adversos , Administração por Inalação , Animais , Neoplasias Ósseas/induzido quimicamente , Neoplasias Ósseas/etiologia , Feminino , Fungicidas Industriais/efeitos adversos , Neoplasias Hepáticas/induzido quimicamente , Neoplasias Hepáticas/etiologia , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/etiologia , Masculino , Ratos , Ratos Wistar , Fatores de TempoRESUMO
Concentration of retinoids was decreased from 24.5 micrograms/100 ml to 13.5 micrograms/100 ml of blood serum in rats with ageing, during 2-11 months; these rats were maintained on a standard ration. Enrichment of rat ration with beta-carotene caused a statistically significant increase in content of retinoids in blood serum from 24.5 micrograms/100 ml to 48.6 micrograms/100 ml within early periods (1-72 hrs), while within later periods (0.25-2 months) the retinoid content was similar to that of control intact animals. After single and, especially, in long-term treatments with beta-carotene dose-dependent deposition of the carotenoid and increase in content of retinoids were detected in liver tissue. Use of white rats is of importance in principle for evaluation of beta-carotene caused modifications of pathological states developed under influence of unsuitable environmental factors.
Assuntos
Carotenoides/metabolismo , Animais , Carotenoides/farmacocinética , Fígado/química , Ratos , Vitamina A/sangue , beta CarotenoAssuntos
Carotenoides/uso terapêutico , Lesões Experimentais por Radiação/prevenção & controle , Protetores contra Radiação/uso terapêutico , Administração Oral , Animais , Carotenoides/administração & dosagem , Radioisótopos de Césio , Feminino , Raios gama , Camundongos , Camundongos Endogâmicos CBA , beta CarotenoRESUMO
The incidence of malignant tumors increased and the average life decreased at remote times following long-term fractionated gamma-irradiation. Life shortening only exhibited a strict dependence on the cumulative radiation dose.
Assuntos
Neoplasias Induzidas por Radiação , Animais , Raios gama , Masculino , Doses de Radiação , Ratos , Ratos EndogâmicosRESUMO
Destructive, inflammatory, sclerotic, compensatory and adaptive, pretumoral and tumoral changes in the respiratory tracts of rats were revealed 180-540 days following a single inhalation of 239PuO2. The thickness of the bronchus wall and the diameter of their lumen remained significantly increased, as compared with the controls of the same age, throughout the entire period of observation.
Assuntos
Poluentes Radioativos do Ar/toxicidade , Poluentes Atmosféricos/toxicidade , Brônquios/efeitos da radiação , Plutônio/toxicidade , Animais , Brônquios/patologia , Brônquios/ultraestrutura , Neoplasias Brônquicas/etiologia , Neoplasias Brônquicas/patologia , Neoplasias Brônquicas/ultraestrutura , Epitélio/patologia , Epitélio/efeitos da radiação , Epitélio/ultraestrutura , Feminino , Neoplasias Induzidas por Radiação/etiologia , Neoplasias Induzidas por Radiação/patologia , Neoplasias Induzidas por Radiação/ultraestrutura , Lesões Pré-Cancerosas/etiologia , Lesões Pré-Cancerosas/patologia , Lesões Pré-Cancerosas/ultraestrutura , Ratos , Ratos Endogâmicos , Fatores de TempoRESUMO
In experiments of on rats a study was made of late effects of chronic action of tritium oxide (3HOH) during 6 months (37 X 10(4) Bq/g/day) and external gamma-radiation (137Cs) which were delivered in comparable daily and cumulative doses. It was shown that 3HOH produced a more pronounced blastomogenic effect. The RBE coefficient of tritium oxide approximated 1, with a reference to the average life shortening, and 4.2 and 2.5, with a reference to the incidence of malignant tumors and leukoses, respectively.
Assuntos
Neoplasias Induzidas por Radiação/etiologia , Trítio , Água , Animais , Radioisótopos de Césio , Raios gama , Leucemia Induzida por Radiação/etiologia , Leucemia Induzida por Radiação/mortalidade , Masculino , Neoplasias Induzidas por Radiação/mortalidade , Doses de Radiação , Ratos , Ratos Endogâmicos , Eficiência Biológica Relativa , Fatores de TempoRESUMO
The report is concerned with a monolayer culture of bone marrow cells of rats in which optimal blastogenic dose (92.5 kBq/kg) induced osteosarcoma. The cell culture showed an enhanced rate of fibroblast-like cell proliferation (increased number of mitoses and symplasts and larger colonies of cells), apparent signs of radiation injury (pathologic mitoses, chromosome aberrations and gaps) as well as an increase in ploidy. Diffusion chamber measurements demonstrated osteogenic precursor-cells in osteosarcoma-bearing rats to be highly capable of bone formation. This relatively high ability seems to occur outside bone marrow as well.