RESUMO
Offspring of male Wistar rats, exposed to continuous magnetic field of 0.5 T1 (3 hours daily during 60 days), did not have significant differences from the control according to such parameters as sex distribution, mortality rates, body mass dynamics, terms of ears coming off, eruption of teeth, onset of hearing and eyes opening. There was a tendency to the reduction of static physical efficiency in holding to the horizontal bar. Increased activity of test animals 30 days old in "the open field" and CNS excitability elevation according to reactions to a sound stress were revealed.
Assuntos
Magnetismo , Animais , Comportamento Animal , Campos Eletromagnéticos/efeitos adversos , Pai , Crescimento , Masculino , Ratos , Ratos Endogâmicos , Fatores de TempoRESUMO
In two experiments male rats were exposed to a constant magnetic field (CMF) of 0.4 T either once for 3 hours or 56 times for the same time (throughout the entire spermatogenetic cycle). During the first week after exposure they were mated with untreated females. Some of the females were sacrificed on their 21st day of gestation. The following parameters were measured: percentage of implantations and resorptions, total fetal lethality, number and weight of alive fetuses, weight of placentas and ovaries, hydration of placentas and fetuses. At birth the duration of gestation, the amount of alive and dead newborns, their weight and distribution in the litter were determined. These parameters were used to evaluate the genetic quality of spermatozoa that were involved in fertilization. The pups were observed during the first month of life. The results obtained suggest that mature spermatozoa are resistant to a single CMF exposure and that this exposure causes no mutations in the gametes which may reduce fetal viability. However, chronic exposure to CMF leads to a small and significant increase of preimplantation lethality of fetuses which may indicate a higher frequency of lethal mutations in the gametes.
Assuntos
Campos Eletromagnéticos , Fenômenos Eletromagnéticos , Comportamento Sexual Animal/efeitos da radiação , Espermatogênese/efeitos da radiação , Animais , Desenvolvimento Embrionário e Fetal/genética , Desenvolvimento Embrionário e Fetal/fisiologia , Desenvolvimento Embrionário e Fetal/efeitos da radiação , Feminino , Morte Fetal/etiologia , Masculino , Mutação , Gravidez , Doses de Radiação , Ratos , Ratos Endogâmicos , Comportamento Sexual Animal/fisiologia , Espermatogênese/genética , Espermatogênese/fisiologia , Fatores de TempoRESUMO
For 30 days rats were exposed daily 3 hrs a day to a constant magnetic field of 1.6 T. The time within which the rats were swimming with a load until they were fatigued was measured and the concentration of catecholamines in blood and adrenals was determined. Two stages of the response to the magnetic field were identified. During the first stage (1-15 days) physical work capacity increased and the reactivity and reserve ability of the sympatho-adrenal system (SAS) grew. During the second stage (30th day and early recovery period) work capacity returned to normal and the SAS reactivity decreased, although the catecholamines stored in the adrenals remained unchanged. These findings indicate that the SAS is involved in mechanisms underlying changes in work capacity and adaptation processes during exposure to a constant magnetic field.
Assuntos
Glândulas Suprarrenais/fisiologia , Magnetismo , Esforço Físico , Sistema Nervoso Simpático/fisiologia , Animais , Epinefrina/análise , Masculino , Norepinefrina/análise , Ratos , Natação , Fatores de TempoRESUMO
Variations in physical endurance of rats exposed to a constant magnetic field of 1.6 T for 3 hours a day during 30 days were investigated. The parameter was measured as the time of swimming with a load making 10% of body weight until complete arrest. The rats exposed once, 5 or 15 times showed a longer time of swimming than the controls. On the 30th day of exposure there was no difference between the experimental and control animals. The data obtained suggest that exposure to a constant magnetic field produces a stimulating effect on physical work capacity during the first 15 days.
Assuntos
Magnetismo , Resistência Física , Animais , Masculino , Esforço Físico , Ratos , Natação , Fatores de TempoRESUMO
The polarographic analysis of biological oxidation in rat skeletal muscles after the 18.5-day flight revealed changes specific for the flight animals: oxidative phosphorylation uncoupling, distinct inertness of energy accumulation 10 hrs after recovery. Tissue respiration inhibition occurred in both flight and synchronous rats suggesting the effect of other than weightlessness factors. In the flight animals the parameters of energy metabolism returned to the prelaunch level within a longer (29 days) time than in the synchronous rats (6 days). Muscles of different function (predominance of fast or slow fibers) showed similar responses of energy metabolism to weightlessness, i. e. inhibition of the intensity and decrease of the energy efficiency of oxidative processes.
Assuntos
Metabolismo Energético , Músculos/enzimologia , Voo Espacial , Animais , Mitocôndrias Musculares/enzimologia , Fosforilação Oxidativa , Consumo de Oxigênio , Polarografia , Ratos , Ratos Endogâmicos , Fatores de Tempo , U.R.S.S.RESUMO
The respiration of mitochondria isolated from mixed skeletal muscles of hindlimbs of rats flown for 18.5 days on Cosmos-936 was investigated polarographically. At R + 10 hours the rate of mitochondrial respiration in different metabolic states during the oxidation of succinic acid and NAD-dependent substrates declined. The enzyme activity of mitochondrial cytochrome oxidase and cytosol lactate dehydrogenase diminished. At R + 25 days both aerobic and anaerobic oxidative processes increased, thus leading to the recovery of the parameters (sometimes they not only returned to the norm but exceeded it).
Assuntos
Metabolismo Energético , Músculos/enzimologia , Voo Espacial , Animais , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , L-Lactato Desidrogenase/metabolismo , Oxirredução , Ratos , Fatores de Tempo , U.R.S.S.Assuntos
Transtornos Hemorrágicos/etiologia , Pancreatite/complicações , Trombose/etiologia , Coagulação Sanguínea , Criança , Colecistite/complicações , Doença Crônica , Colite/complicações , Duodenopatias/complicações , Enterite/complicações , Fibrinólise , Transtornos Hemorrágicos/fisiopatologia , Humanos , Pancreatite/fisiopatologia , Síndrome , Tromboelastografia , Trombose/fisiopatologiaRESUMO
As a result of a combined effect of prolonged weightlessness and ionizing radiation at a dose of 800 rad aboard the biosatellite Cosmos-690, the recovery time of certain parameters of fluid-electrolyte metabolism (hydration of the body, balance of sodium, potassium, calcium) was longer than that for the animals which flew abroad the biosatellite Cosmos-605.