RESUMO
An investigation of the influence of chronic low-intensity irradiation with 0.25 Gr dose and of a mixture of heavy metal salts both apart and together, as well as when correcting with a natural adaptogen such as Spirulina platensis, on passive and active transport of potassium and the work efficiency of Na,K-pump in slices of brain cortex was the problem of this study. As a biological model for in vivo researches on molecular-cellular level the thin layers of a rat brain cortex were used. It was shown that both radiation and chemical factors cause reliable changes of passive membrane permeability and operation of Na,K-pump, whose function is the maintenance of the certain gradient of potassium ions on the plasmatic membrane, the normalization of ion homeostasis, the stabilization of membranous potential. The analysis of calculated indexes of passive and of active ion transport show that at modification of X-rays influence with a mixture of heavy metal salts exactly the last makes the main contribution to efficiency decrease of energy-dependent transport of potassium. The natural adaptogen spirulina renders a better effect in the case of toxic action of the mixture of heavy metal salts, enlarging not only active transport of potassium ions, but its efficiency as well.
Assuntos
Permeabilidade da Membrana Celular/efeitos dos fármacos , Córtex Cerebral/efeitos dos fármacos , Metais Pesados/antagonistas & inibidores , Preparações de Plantas/farmacologia , Potássio/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Spirulina/química , Animais , Transporte Biológico Ativo/efeitos dos fármacos , Transporte Biológico Ativo/efeitos da radiação , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Membrana Celular/efeitos da radiação , Permeabilidade da Membrana Celular/efeitos da radiação , Córtex Cerebral/efeitos da radiação , Masculino , Metais Pesados/toxicidade , Ratos , Ratos Endogâmicos , Raios XRESUMO
Chronic combined exposure to ionizing radiation with dose of 0.25 Gy and cadmium chloride or atrazine to be present in drinking water at five-fold Limited Permissible Concentration (LPC) values led to the additively reduced intercellular K+ level in rat brain, that was at first choice caused by the active ion transport disorders in the case of irradiation, and by the changes in membrane permeability in the case of toxic loading. Applying of beta-carotene oil and bee pollen both abolished radiation effects, but no chemical toxicant ones. Authors supposed the selective action of the observed drugs to be connected with antioxidant activities of them.
Assuntos
Antioxidantes/farmacologia , Atrazina/toxicidade , Encéfalo/metabolismo , Herbicidas/toxicidade , Transporte de Íons/efeitos dos fármacos , Potássio/metabolismo , Protetores contra Radiação/farmacologia , beta Caroteno/farmacologia , Animais , Abelhas , Encéfalo/efeitos dos fármacos , Encéfalo/efeitos da radiação , Cloreto de Cádmio/toxicidade , Transporte de Íons/efeitos da radiação , Masculino , Pólen , Ratos , Ratos WistarRESUMO
As a result of the study of both the acetylcholine (10(-10) M; 10(-6) M) and gamma-aminobutyric acid (10(-9) M; 10(-5) M) effects on active K+ transport in rat brain cortex slices using any selective antagonists of cholinoreceptors (ChR) and GABA-receptors (GABA-R) it had been shown that after whole-body 25 cGy irradiation (1.75 mGy/min) metabotropic muscarinic ChR and GABAB-R were involved into processes of neurotransmitter modulation, whereas under the normal conditions they were mediated via ionotropic nicotinic ChR and GABAA-R. Observed changes were supposed to be an adaptive reaction. Perhaps, postirradiation structure-functional disorders in receptors were pointed as one of the reasons leading to essential changes in the interneuronal metabolic communication processes in CNS.
Assuntos
Encéfalo/metabolismo , Encéfalo/efeitos da radiação , Potássio/metabolismo , Receptores Colinérgicos/metabolismo , Receptores de GABA-A/metabolismo , Receptores de GABA-B/metabolismo , Acetilcolina/metabolismo , Acetilcolina/farmacologia , Adaptação Biológica , Animais , Encéfalo/ultraestrutura , Membrana Celular/metabolismo , Membrana Celular/efeitos da radiação , Masculino , Neurônios/metabolismo , Neurônios/efeitos da radiação , Ratos , Ratos Wistar , Irradiação Corporal Total , Ácido gama-Aminobutírico/metabolismo , Ácido gama-Aminobutírico/farmacologiaRESUMO
It had been found that both the single prolonged irradiation and chronic (fractionated) one with doses of 25 and 50 cGy (1.75 mGy/min) caused essential modification of the biphase modulative effects of acetylcholine and gamma-aminobutyric acid upon K+ level in rat brain cortex slices to be compared to the acute lethal irradiation influence. The results of model experiments showed saturated fatty acids to be significant for the changes in regulative functions of nerve cell membranes after exposure to low dose-rate radiation.
Assuntos
Encéfalo/efeitos da radiação , Neurotransmissores/efeitos da radiação , Acetilcolina/farmacologia , Acetilcolina/efeitos da radiação , Animais , Encéfalo/citologia , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Relação Dose-Resposta a Droga , Relação Dose-Resposta à Radiação , Íons , Masculino , Neurotransmissores/farmacologia , Potássio/metabolismo , Potássio/efeitos da radiação , Ratos , Ratos Wistar , Fatores de Tempo , Ácido gama-Aminobutírico/farmacologia , Ácido gama-Aminobutírico/efeitos da radiaçãoRESUMO
Single and/or chronic X-ray low-intensity irradiation in doses from 0.01 up to 0.5 Gy invokes non-linear, oscillatory changes of K+ content in a native tissue of rat brain, and also of Na,K-pump activity in slices of rat brain cortex, incubated in vitro. It is found out that effects of separately taken equal doses of single and chronic exposure are of unequal means or of diverse directions. Thus the single irradiation is characterized by the lower degree of postradiation recovery processes.
Assuntos
Encéfalo/metabolismo , Encéfalo/efeitos da radiação , Potássio/metabolismo , Animais , Transporte Biológico Ativo , Córtex Cerebral/metabolismo , Córtex Cerebral/efeitos da radiação , Interpretação Estatística de Dados , Técnicas In Vitro , Masculino , Doses de Radiação , Ratos , Ratos Wistar , ATPase Trocadora de Sódio-Potássio/metabolismo , Fatores de TempoRESUMO
It was shown that chronic 0.25 Gy irradiation of rats (0.01 Gy/day) at background of heavy metal penetration (Cu2+, 20 mg/l or Co2+, 5 mg/l) with drinking water had caused significant accumulation of the free-radical products proportional to exhausting antioxidant and oxidizing-reduction potential in various organs and tissues. Radiation was shown to be primary harmful factor for the brain, spleen, lungs, and blood plasma, whereas the liver and heart muscle were affected with chemicals at first. Under prolonged unfavourable influence the biochemical changes observed were sustainable and progressing that satisfied to transformation of protective-adaptive reactions into prepathology stage.
Assuntos
Adaptação Fisiológica/efeitos dos fármacos , Adaptação Fisiológica/efeitos da radiação , Cobalto/toxicidade , Cobre/toxicidade , Animais , Antioxidantes/metabolismo , Antioxidantes/efeitos da radiação , Cobalto/farmacocinética , Cobre/farmacocinética , Relação Dose-Resposta à Radiação , Radicais Livres/metabolismo , Radicais Livres/efeitos da radiação , Oxirredução/efeitos dos fármacos , Oxirredução/efeitos da radiação , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Fatores de Tempo , Distribuição Tecidual/efeitos dos fármacos , Distribuição Tecidual/efeitos da radiaçãoRESUMO
The effect of chronic low dose-rate irradiation with X-rays up to total doses of 2.58, 5.16, 6.46, 7.75, 10.32, 12.92 mC/kg on glutathione content and glutathione-S-transferase activity in Wistar rats organs, different by radiosensitivity, was studied 1 h after exposure. It has been shown that level of oxidized and reduced glutathione forms was not changed after exposure to 2.58 mC/kg, was enhanced in kidney and brain tissues after exposure to 5.16 and 6.46 mC/kg and was decreased in brain, lungs, small intestines and blood serum after ray exposures to higher doses. Inhibition of glutathione-S-transferase activity was found in liver, kidneys and spleen.
Assuntos
Glutationa Transferase/efeitos da radiação , Glutationa/efeitos da radiação , Lesões Experimentais por Radiação/metabolismo , Animais , Doença Crônica , Relação Dose-Resposta à Radiação , Fluorometria , Glutationa/análise , Glutationa Transferase/análise , Tolerância a Radiação/fisiologia , Ratos , Ratos Wistar , Espectrofotometria Ultravioleta , Fatores de TempoRESUMO
Effect of chronic low dose X-ray irradiation (total doses of 2.58, 5.16, 6.46, 7.75, 10.32 and 12.92 mC/kg) on gamma-glytamyltranspeptidase activity was investigated in rat organs and tissues which were different by radiosensitivity. Enzymatic activity was measured one hour after exposure. The increase in enzymatic activity was found in brain, liver, lungs, spleen, blood serum and partially in kidneys under all exposure doses. Exposure to 2.58, 5.16 and 12.92 mC/kg inhibited gamma-glutamyltranspeptidase activity in small intestines.
Assuntos
gama-Glutamiltransferase/efeitos da radiação , Animais , Relação Dose-Resposta à Radiação , Masculino , Tolerância a Radiação , Ratos , Ratos Wistar , Fatores de Tempo , gama-Glutamiltransferase/análiseRESUMO
Rates of lipid peroxidation and endogenous phospholipase hydrolysis were studied under conditions of simultaneous moderate hypothermia and traumatic ischemia of muscles. Activation of the reactions studied, which was expressed as an increase in content of malonic dialdehyde and free fatty acids, was of importance for pathogenesis of muscles impairments occurring in trauma. Local cooling affected favourably these patterns of lipid metabolism.
Assuntos
Hipotermia Induzida , Isquemia/metabolismo , Peroxidação de Lipídeos , Músculos/lesões , Fosfolipases/metabolismo , Animais , Ácidos Graxos não Esterificados/metabolismo , Hidrólise , Isquemia/etiologia , Malondialdeído/metabolismo , Músculos/irrigação sanguínea , Músculos/metabolismo , Ratos , Ratos EndogâmicosRESUMO
A study was made of the effect of irradiation with a superlethal dose of 9.288 C/kg on oxidative phosphorylation in morphologically and functionally different parts of the central nervous system. The CNS-syndrome was shown to develop against the background of a pronounced injury to energy processes in the brain. It is supposed that the impairment of the energy supply of active ion transport systems plays an important role in the dysfunction of the brain induced by high-level radiation.
Assuntos
Sistema Nervoso Central/efeitos da radiação , Metabolismo Energético/efeitos da radiação , Fosforilação Oxidativa/efeitos da radiação , Animais , Transporte Biológico Ativo/efeitos da radiação , Sistema Nervoso Central/metabolismo , RatosRESUMO
A study was made of the effect of ionizing radiation (0.013 C/kg) on Na, K- and Ca, Mg-ATPase activity in membranes of rat organs differing in radiosensitivity. It was shown that radiation mainly caused activation of enzymes that was most pronounced in brain membranes.
Assuntos
ATPase de Ca(2+) e Mg(2+)/metabolismo , ATPases Transportadoras de Cálcio/metabolismo , Membrana Celular/efeitos da radiação , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Transporte Biológico Ativo/efeitos da radiação , Membrana Celular/enzimologia , Masculino , Ratos , Ratos EndogâmicosRESUMO
The effects in vivo and in vitro of the radioprotective agents (MEA, AET, serotonin, dopamine, and histamine) on mitochondrial ATPase activity of rat brain and liver have been investigated. The enzyme activity has been found to be inhibited for the most. Possible mechanisms of the effects observed are discussed.
Assuntos
Adenosina Trifosfatases/metabolismo , Encéfalo/enzimologia , Mitocôndrias Hepáticas/enzimologia , Mitocôndrias/enzimologia , Protetores contra Radiação/farmacologia , Animais , Encéfalo/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias Hepáticas/efeitos dos fármacos , Ratos , Ratos EndogâmicosRESUMO
The postirradiation changes in the adenine nucleotide content and energy charge in large hemispheres of rat brain have been investigated. Dose dependent disturbances have been found in the adenine nucleotide system. Mechanisms of changes in the energy status of nerve cells in radiation disease are discussed.
Assuntos
Nucleotídeos de Adenina/efeitos da radiação , Encéfalo/efeitos da radiação , Metabolismo Energético/efeitos da radiação , Nucleotídeos de Adenina/análise , Animais , Transporte Biológico Ativo/efeitos da radiação , Encéfalo/metabolismo , Química Encefálica/efeitos da radiação , Relação Dose-Resposta à Radiação , Ratos , Ratos Endogâmicos , Fatores de TempoRESUMO
The in vivo and vitro studies have demonstrated that Na,K-ATPase activity in membranes of thymus, spleen, small intestine mucosa, liver, kidneys, and brain cortex of rats is inhibited by the effect of radioprotective agents: serotonin, dopamine, histamine, MEA, and AET.
Assuntos
Protetores contra Radiação/farmacologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Transporte Biológico Ativo/efeitos dos fármacos , Transporte Biológico Ativo/fisiologia , Técnicas In Vitro , Masculino , Ratos , Ratos Endogâmicos , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidoresRESUMO
The effect of lethal and superlethal doses of ionizing radiation (0.206, 0.309, and 9.288 C/kg) on ATPase activity of rat brain mitochondria has been investigated. The results obtained indicate that ionizing radiation causes appreciable, depending on the dose, changes in ATPase of brain mitochondria.
Assuntos
Adenosina Trifosfatases/metabolismo , Encéfalo/efeitos da radiação , Mitocôndrias/efeitos da radiação , Animais , Transporte Biológico Ativo/efeitos da radiação , Encéfalo/enzimologia , Mitocôndrias/enzimologia , RatosRESUMO
The effect of ionizing radiation of lethal (0.31 C/kg) and superlethal (9.288 C/kg) doses on Mg2+, Ca2+-ATPase activity in plasma membranes of brain cortex and cerebellum has been studied. As is shown, ionizing radiation has an inhibitory effect on the enzyme activity which is most pronounced and irreversible after exposure to superlethal doses.
Assuntos
Encéfalo/metabolismo , ATPase de Ca(2+) e Mg(2+)/antagonistas & inibidores , ATPases Transportadoras de Cálcio/antagonistas & inibidores , Lesões Experimentais por Radiação/metabolismo , Animais , Transporte Biológico Ativo/efeitos da radiação , Encéfalo/enzimologia , ATPase de Ca(2+) e Mg(2+)/efeitos da radiação , Cálcio/metabolismo , ATPases Transportadoras de Cálcio/efeitos da radiação , Membrana Eritrocítica/enzimologia , Lesões Experimentais por Radiação/enzimologia , Ratos , Ratos EndogâmicosRESUMO
Whole-body X irradiation with doses of 0.155 and 0.310 C/kg was shown to modify in different ways the activating effects of noradrenaline and serotonin, as well as a biphase effect of dopamine (5.10(-8)--1.5.10(-3) M) on Na,K-pump of neuronal membranes. The resulting effect was a function of a combination of radiation doses and neurotransmitter concentrations and thus showed different modes of interaction between neurotransmitter and ion-transport systems of brain cells in radiation sickness. The authors discuss possible molecular mechanisms of radiation modification of the functional interaction between the neurotransmitter and the active ion-transport systems in nerve cells.
Assuntos
Encéfalo/efeitos dos fármacos , Encéfalo/efeitos da radiação , Dopamina/farmacologia , Norepinefrina/farmacologia , Serotonina/farmacologia , ATPase Trocadora de Sódio-Potássio/efeitos dos fármacos , ATPase Trocadora de Sódio-Potássio/efeitos da radiação , Animais , Transporte Biológico Ativo/efeitos dos fármacos , Transporte Biológico Ativo/efeitos da radiação , Encéfalo/metabolismo , Relação Dose-Resposta à Radiação , Masculino , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Neurônios/efeitos da radiação , Potássio/metabolismo , Potássio/efeitos da radiação , Ratos , Ratos Wistar , Fatores de Tempo , Irradiação Corporal TotalRESUMO
A study was made of the free fatty acid (FFA) content of homogenates of brain, thymus, liver, kidneys, erythrocytes, small intestine mucosa, and spleen of X-irradiated (7.76 Gy) rats. The increased FFA content was exhibited by all the organs under study. The increase was maximum in the thymus. Calcium ions were shown to play a defined role in the radiation enhancement of endogenous phospholipase hydrolysis.
Assuntos
Fosfolipases/efeitos da radiação , Lesões Experimentais por Radiação/enzimologia , Animais , Ácidos Graxos não Esterificados/metabolismo , Ácidos Graxos não Esterificados/efeitos da radiação , Hidrólise , Fosfolipases/metabolismo , Ratos , Fatores de Tempo , Distribuição Tecidual/efeitos da radiaçãoRESUMO
A study was made of the influence of ionizing radiation of 0.31 C/kg on the kinetic parameters showing the activity of brain Na, K-ATPase preparation to be a function of ion-regulator concentration. The use of the new method for the analysis of the enzyme cation centers permitted to estimate that whole-body irradiation of rats with the above dose did not cause in vitro a substantial change in the pattern of Na, K-ATPase activation by Na and K ions.
Assuntos
Encéfalo/enzimologia , Lesões Experimentais por Radiação/enzimologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Transporte Biológico Ativo/efeitos da radiação , Ativação Enzimática/efeitos dos fármacos , Íons , Potássio/farmacocinética , Potássio/fisiologia , Ratos , Ratos Endogâmicos , Sódio/farmacocinética , Sódio/fisiologiaRESUMO
A study was made of the effect of X-radiation (0.31 C/kg and 3.875 C/kg) on Na, K-ATPase in fractions enriched with neurons and neuroglia. The results show the impairment of the neuronal-glial relationship in Na, K-ATPase activity. The most important differences in the pattern of changes in Na, K-ATPase system of brain cells were followed up after irradiation with lethal and sublethal doses.