RESUMO
It is known that several hours of intensive muscle tension result in accumulation of muscle derived enzymes and structural proteins (see review by Clarkson, 1997). We have assumed that, firstly, acute exposure to hypergravity may induce accumulation of serum creatine phosphokinase (CPK), and, secondly, level of that accumulation may be considerably altered after long term hypokinesia.
Assuntos
Repouso em Cama , Creatina Quinase/metabolismo , Decúbito Inclinado com Rebaixamento da Cabeça , Hipergravidade , Animais , Creatina Quinase/sangue , Eletrocardiografia , Frequência Cardíaca , Macaca mulatta , Músculo Esquelético/enzimologia , Pulso ArterialAssuntos
Descompressão , Hemodinâmica , Pressão Negativa da Região Corporal Inferior , Respiração , Ausência de Peso , Adulto , Humanos , Masculino , PosturaRESUMO
We present the resuIts of manned studies in which test subjects were exposed to simulated zero g (water immersion or head-down tilt at -6 degrees) and head-to-feet acceleration. The findings give evidence that humans have different individual tolerances to an acceleration of +3 Gz after exposure to zero g, whether simulated by immersion or by head-down tilt. The paper discusses the role of functional relationship between water balance and cardiac output in the establishment of adaptive reactions to simulated zero g.
Assuntos
Adaptação Fisiológica , Simulação de Ausência de Peso , Aceleração , Adulto , Pressão Sanguínea , Débito Cardíaco , Decúbito Inclinado com Rebaixamento da Cabeça , Frequência Cardíaca , Humanos , Hipergravidade , Imersão , Masculino , Água , Equilíbrio HidroeletrolíticoRESUMO
We present the results of manned studies in which test subjects were exposed to simulated zero g (water immersion or head-down tilt at -6 degrees) and head-to-feet acceleration. The findings give evidence that humans have different individual tolerances to an acceleration of +3 Gz after exposure to zero g, whether simulated by immersion or by head-down tilt. The paper discusses the functional relationship between water balance and cardiac output in the establishment of adaptive reactions to simulated zero g.
Assuntos
Adaptação Fisiológica , Hemodinâmica/fisiologia , Hipergravidade , Simulação de Ausência de Peso , Adulto , Medicina Aeroespacial , Pressão Sanguínea , Débito Cardíaco , Centrifugação , Decúbito Inclinado com Rebaixamento da Cabeça , Frequência Cardíaca , Humanos , Imersão , Masculino , Água , Equilíbrio HidroeletrolíticoRESUMO
The prophylactic effect on adult human males of intermittent acceleration against physiological deconditioning in weightlessness simulated by water immersion was studied at +0.8, +1.2, and +1.6 g. These prophylactic exposures reduced renal excretion of fluid and plasma volume changes, and increased venous compliance and the time at which the subjects could tolerate an acceleration field of +3 g.
Assuntos
Aceleração , Adaptação Fisiológica , Deslocamentos de Líquidos Corporais/fisiologia , Hipergravidade , Contramedidas de Ausência de Peso , Simulação de Ausência de Peso , Adulto , Descondicionamento Cardiovascular/fisiologia , Centrifugação , Humanos , Imersão , Masculino , Urina , Água , Equilíbrio HidroeletrolíticoRESUMO
A 56-day immersion experiment in which two subjects participated was carried out. During the experiment the preventive effect of periodic acceleration combined with exercise and water-salt intake was assessed. Simulating an increased gravitational field, exposure to acceleration increased the static component of the load upon the musculo-skeletal system, increased the gradient of the blood hydrostatic pressure, activated mechanisms responsible for the venous return to the heart, stimulated systems regulating antidiuretic and antisodiumdiuretic reflexes. Involvement of these mechanisms restored haemodynamic parameters, fluid-electrolyte balance and blood coagulability. The prophylactic effect of acceleration was enhanced if combined with exercise and supplemented water-salt intake.
Assuntos
Terapia por Exercício , Hipergravidade , Imersão/efeitos adversos , Cloreto de Sódio/uso terapêutico , Contramedidas de Ausência de Peso , Simulação de Ausência de Peso/efeitos adversos , Aceleração , Volume Sanguíneo/efeitos dos fármacos , Volume Sanguíneo/fisiologia , Cálcio/metabolismo , Cálcio/urina , Centrifugação , Creatinina/metabolismo , Creatinina/urina , Frequência Cardíaca/fisiologia , Humanos , Masculino , Potássio/metabolismo , Potássio/urina , Cloreto de Sódio/urina , Água , Equilíbrio Hidroeletrolítico/efeitos dos fármacos , Equilíbrio Hidroeletrolítico/fisiologiaRESUMO
Test subjects covered with a waterproof highly elastic cloth were exposed to 13-day water immersion up to the neck. They were divided into two groups. The first (control) group consisting of six persons was exposed to immersion alone and the second (experimental) group was exposed daily to accelerations of 0.6-2 Gz for 60-90 min during the last 6 days of immersion. Before and after immersion all the test subjects were exposed to +3 Gz for 5 min which served as a provocative test. These experiments give evidence that the use of dry immersion allows experimentation during prolonged immersion without concomitant complications. Variations in the physiological parameters (cardiovascular system, fluid-electrolyte balance, blood-coagulatory system) are indicative of the preventive effect of periodic accelerations during 13-day immersion.
