RESUMO
In this study we evaluated the effects of the administration of a vitamin D3 preparation 'Videchol' to chronically irradiated rats (1 cGy day(-1)) by the assessment of the activities of several glycolytic enzymes: lactic dehydrogenase (LDH) (EC 1.1.1.28), pyruvate kinase (PK) (EC 2.7.1.40) and hexokinase (HK) (EC 2.7.1.1), in populations of erythroid and myeloid bone marrow cells. Videchol treatment of irradiated rats led to the normalisation of HK and LDH activity at cumulative doses of around 30 cGy in granulocyte-monocyte cells and to normalisation of LDH and PK activities in erythroid cells starting at 20 cGy in comparison with irradiated rats who did not receive Videchol. The reaction kinetic parameters of LDH in erythrocytes changed according to the redistribution pattern of the isozymes throughout the different stages of the experiment. The administration of Videchol to irradiated rats led to a rearrangement of the LDH isozymes ratio characterised by kinetic properties more comparable to those of the controls. Thus, vitamin D3 appears to induce a normalisation of carbohydrate metabolism in rats chronically irradiated with low dose-rate ionising radiation.
Assuntos
Medula Óssea/metabolismo , Colecalciferol/farmacologia , Eritrócitos/metabolismo , Glicólise/efeitos da radiação , Animais , Medula Óssea/efeitos dos fármacos , Eritrócitos/efeitos dos fármacos , Hexoquinase/metabolismo , Isoenzimas/metabolismo , L-Lactato Desidrogenase/metabolismo , Piruvato Quinase/metabolismo , Doses de Radiação , Ratos , Ratos Wistar , Irradiação Corporal TotalRESUMO
The structural and functional state of blood erythrocytes in people exposed to radiation during Chernobyl NPP accident was studied two or six years later. The changes in oxygen transport system of erythrocytes and in the ratio between some organic phosphate fractions were observed. The beta-carotene per os administration to rats during low-level irradiation increased hemolytic stability and activity of glycolytic enzymes, that bears witness to the increasing of organism adaptive reactions at provitamin administration during irradiation.
Assuntos
Eritrócitos/efeitos da radiação , Centrais Elétricas , Liberação Nociva de Radioativos , Adaptação Fisiológica , Adulto , Animais , Antioxidantes/administração & dosagem , Eritrócitos/enzimologia , Eritrócitos/metabolismo , Eritrócitos/fisiologia , Feminino , Glicólise , Humanos , Doses de Radiação , Ratos , Espectrofotometria , Fatores de Tempo , Ucrânia , beta Caroteno/administração & dosagemRESUMO
An abnormality in the primary structure of dog haemoglobin was observed 1-20 days after their whole body irradiation with 190 keV X-rays (4.0 Gy). It consisted in a substitution of tryptophane residue in position 15 of the beta-chain for serine. The percentage of abnormal beta-chains in different time intervals after irradiation was determined. The structural changes have functional impact: an increasing haemoglobin affinity to oxygen. This could be explained on the basis of changes in the tertiary structure of haemoglobin, which may result from the substitution Trp 15----Ser15 in the beta-chain which may influence the haeme ability to bind oxygen.
Assuntos
Hemoglobinas/efeitos da radiação , Aminoácidos/análise , Animais , Cães , Globinas/análise , Globinas/efeitos da radiação , Hemoglobinas/metabolismo , Oxigênio/metabolismo , Peptídeos/análise , Conformação Proteica/efeitos da radiação , Tripsina , Irradiação Corporal TotalRESUMO
Heterogeneity of dog hemoglobin is established with application of chromatographic analysis. Ionizing radiation (4 Grey) induces no changes in the ratio of hemoglobin components. The comparative dactylographical analysis of the hemoglobin components in norm and in different periods after irradiation revealed differences in responses to tryptophan in peptide T-25. The changes found are connected with disturbances in the structure of the DNA molecule as well as with modification of the protein molecule under conditions of radiation injury.
