Проведён количественный протеомный анализ 50 образцов плазмы крови здоровых добровольцев, которые прошли всестороннее медицинское обследование и были признаны годными к космическим полётам. В результате направленного масс-спектрометрического анализа удалось зарегистрировать сигнал для 128 белков, что составляет почти 40% от общего числа продуктов генов этой хромосомы. Анализ межиндивидуальной изменчивости концентрации белков хромосомы 13 показал присутствие пула из 41 белка с низкой вариабельностью (CV 30%), которые потенциально могут быть использованы в качестве биомаркёров.

We have studied metabolic responses of six male volunteers who were exposed to hypoxic nitrogen–oxygen and argon–oxygen respiratory mixtures under hermetic chamber conditions for a long time. We measured the values of 44 biochemical parameters of venous blood, which reflected the state of different parts of metabolism, as well as the state of organs and tissues. Under the conditions of argon–oxygen respiratory mixture with the level of oxygen of 12.8% within the first five days and 12.0% from six to ten days of the experiment, the activation of processes of anaerobic glycolysis and lipolysis with the development of metabolic acidosis was observed. Against this background, biochemical signs of unfavorable changes in the myocardium were recorded. When we used the nitrogen–oxygen respiratory mixture with the level of oxygen of 13.0% during the first five days of the experiment and 12.1% from the sixth to the tenth day, these changes were expressed much more significantly: the activation of lipolysis and a decrease in the level of serum iron were observed and the signs of damage of mitochondria, depression of the kidney function, and development of hypodynamia were recorded. Complete stabilization of metabolic processes was reached only after seven to eight days of the recovery period for both mixtures. These findings lead to the conclusion that it is physiologically more preferable to use oxygen–argon respiratory mixtures at small immersion depths.

Quantitative proteomic analysis of 50 blood plasma samples of healthy volunteers who underwent a comprehensive medical examination and were found eligible for space flights was performed. As a result of directed mass spectrometric analysis, signals for 128 proteins, which accounted for nearly 40% of the total number of chromosome 13 gene products, were detected. The analysis of interindividual variation of concentrations of chromosome 13 proteins showed the presence of a pool comprising 41 proteins with a low variation (CV < 30%), which can potentially be used as biomarkers.

The results of studying the system of the osteoprotegerin/receptor activator of nuclear factor kappa-B ligand (OPG/RANKL) in 22 Russian cosmonauts after long-term (124–199 days) International Space Station missions are presented. It was found that early readaptation period is associated with changes in the serum concentrations of OPG and RANKL and the production rate of OPG and RANKL in phytohemagglutinin (PHA)-stimulated and non-stimulated mononuclear cells of peripheral blood in vitro. The extent of these changes varied in different subjects. Our data suggest that the OPG/RANKL cytokine system takes part in the processes of bone remodeling in cosmonauts after long-term missions.

Hemostasis has been studied in the course of long-term (520 days) isolation in hermetic chamber. Measured parameters included activated partial thromboplastin time (APTT), international normalized ratio (INR), thrombin time (ТT); concentrations of fibrinogen (FBG), plasminogen (PG), Willebrand factor (WF), tissue factor pathway inhibitor (TFPI), tissue plasminogen activator (TPA), and thrombomodulin (ТМ); activities of the coagulation cascade factors II, V, VII, X, VIII, IX, XI, and XII, antithrombin III (ATIII), protein С (PC), С1-inhibitor (С1), α 2 -antiplasmin (АP), TPA and TFPI. The investigation revealed a diversity of changes in plasma FBG concentration, slower blood coagulation in the intrinsic pathway and in final stage, and a relative rise in the activities of ATIII and PC-inhibited factors. The remaining parameters exhibited different trends.

Atomic emission spectral analysis with inductively coupled argon plasma was used to measure contents of iron, zinc, stable strontium, and lithium in blood serum and its ultrafiltered fraction, as well as the level of their excretion in 24-h urine and hair, in a ground-based experiment simulating space flight conditions. The monitoring of iron levels of serum and its ultrafiltered fraction has shown a proper balance between the indicated parameters at all stages of the experiment. The iron forms bound to protein carriers were identified only in blood serum. The study in the conditions of the experiment has shown the dependence of blood serum zinc content on the nutritional status. The level of stable strontium excretion with 24-h urine can serve as a biological indicator of changes in its homeostasis. The experimental conditions have not been found to affect the form of serum lithium; i.e., lithium was invariably present in the ionized state and its content remained equal to the amount of ultrafiltered lithium in all blood samples investigated in all experimental periods.

In the Mars-500 experiment on remote space flight simulation, atomic emission spectral analysis with inductively coupled argon plasma was used to measure serum copper and its ultrafiltrated fraction. It was shown that, in contrast to baseline data, the Cu serum level varied within the normal physiological boundaries throughout the entire simulation experiment. These variations were syncronized in all the serum samples. In several periods of the experiment, reduction in serum Cu within the baseline range was equivalent to simultaneous reduction in ceruloplasmin. Amount of free Cu (ultrafiltration) fraction, i.e., that not bound to the blood serum proteins, was constant at all times. Since the simulation experiment is not a perfect analogy of space flight because of non-reproducibility of some factors, ionizing radiation specifically, we should take into consideration shifts in the serum copper balance caused by the action of space radiation on the human body. Radiation-induced copper imbalance in the blood serum is not only a marker of disturbed oxidase function of blood, but also points to a mechanism of further pathological outcome of toxic excessive copper accumulation in the brain, liver and kidney.

In this study, which was carried out as part of the Mars-500 international project, six men at the age of 28 to 39 years were isolated in a pressure chamber for 520 days. Their parameters of the antioxidant system, including concentration of bilirubin, uric acid, and the total antioxidant capacity of blood plasma, were measured. The maximal values of the parameters studied have been found during stressful periods of the experiment: adaptation to the conditions of the pressure chamber, imitation of a landing on the Mars surface, and change of a diet. When homeostasis was restored, the parameters stabilized at the slightly lower level than the initial values measured before the isolation. Therefore, the dynamics of the water-soluble component of the antioxidant system adequately reflects the state of homeostatic responses of the body under the conditions of 520-day isolation and demonstrates that effects of the factors of pressure chamber have been compensated.

Total and ionized magnesium in the blood serum and daily urine were determined before (baseline values) and on days 30, 60, and 105 of the experiment with a 105 day of isolation and confinement (Mars-105). Magnesium in hair was investigated before (baseline values) and on day 105 of the experiment. The investigations were performed using atomic emission spectrometry with inductively coupled argon plasma. Changes in the magnesium level were the largest during the first 30 days of the experiment. The reduction of serum magnesium level was mainly due to the fall of the ionized fraction. In the body, magnesium is controlled by the ion-regulatory function of the kidneys and varies between individuals. The levels of ionized magnesium in the blood serum and those excreted in daily urine can serve as indicators of stress resistivity.

Electromyostimulation and mechanical stimulation of the foot were used to prevent support load deficiency during a seven-day “dry” immersion experiment. Partial tromboplastin time, prothrombin time, prothrombin index, international normalized ratio, thrombin time (TT), as well as the concentrations of fibrinogen, soluble fibrin monomer complexes, D-dimer (DD), and plasminogen (PG), and the activity of antithrombin III (ATIII), protein C (PC), and α2-antiplasmin (AP) were determined. Immersion without any prophylactic procedures (control) did not evoke significant changes in the hemostatic system, but a decrease in ATIII, PS, and PG levels was observed during re-adaptation. Mechanical stimulation of the foot did not have a significant impact on the functioning of the hemostatic system during immersion, while the use of electromyostimulation during immersion promoted an increase in procoagulant and fibrinolytic activity of blood plasma.

The paper is devoted to the hemostasis studies in the course of long-term (520 d) isolation in an airtight chamber. Measured parameters included activated partial thromboplastin time (APTT), international normalized ratio (INR), thrombin time (TT); concentrations of fibrinogen (FBG), plasminogen (PG), Willebrand factor (WF), tissue factor pathway inhibitor (TFPI), and tissue plasminogen activator (TPA), thrombomodulin (TM); activities of the coagulation cascade factors (II, V, VII, X, VIII, IX, XI, XII), antithrombin III (ATIII), protein C (PC), C1-inhibitor (C1), α2-antiplasmin (AP), TPA and TFPI. The investigation revealed a diversity of changes in the plasma fibrinogen concentration, slower blood coagulation in the intrinsic pathway and the final stage, and a relative rise in the activities of ATIII and PC-inhibited factors. The rest parameters showed different trends.

In an experiment with space flight simulation, atomic emission spectral analysis with inductively coupled argon plasma was employed to measure iron, zinc, stable strontium and lithium in blood serum and its ultrafiltered fraction, and excretion with daily urine and hair. Monitoring of serum iron and its ultraviolet fraction showed good balance of these parameters in all periods of the experiment. Blood serum was found to contain exclusively iron bound with protein carriers. In the experiment, serum zinc was distinctively dependent on the nutrient status. Stable strontium excretion with daily urine can be a biological indicator of its homeostasis. The experiment factors had no effect on the lithium form in serum, i.e. lithium was invariably present in the ionized form and in quantities equal to ultrafiltered lithium in all blood samples in all periods of the experiment.

The effect of factors of a hermetic chamber with a modified atmosphere on the hemostasis system was studied in order to evaluate and to compare different diving breathing gases. The parameters characterizing procoagulant, anticoagulant, and fibrinolytic components of hemostasis were determined by clotting, chromogenic, and immunological methods. The test exposure did not significantly affect activity and the regulatory potential of hemostasis. However, nitrogen-oxygen and argon-oxygen hypoxic diving gases exerted different effects on hemostasis, which were especially distinct in the recovery period.

Consumed NaCl was rationed and integral impedancemetric, psychological, and hormonal studies were performed in six male volunteers 25 to 40 years old before, during, and after an experiment with 105-day isolation and confinement. Every 30 days blood collection for hormonal measurements was combined with filling in Cattell’s 16 personality factor questionnaire. The parameters of total body fluid, body mass, basic exchange, specific hydration and basic exchange were determined. The results showed that the experimental conditions did not affect significantly the body composition, metabolism, and its neurohumoral regulation. The metabolic variations were largely associated with motivation for and value orientation in accommodation, to the permissible extent, of the controlled diet and work/rest schedule to personal needs. In addition, it was found that evolution of the psychophysiological status of humans in isolation and confinement is governed primarily by personality characteristics and, to a less degree, by the specifics and duration of exposure to the artificial environment. Thus, in the opinion of the volunteers, the normoxic, normobaric and slightly hypercapnic (0.15–0.65% CO2) atmosphere was comfortable and harmless to health. The analysis of the whole data array confirmed the expressed interrelation between neuroendocrine and psychophysiological parameters as well as shifts in body basic exchange and mass, salt intake, and hydration rate in the conditions of isolation and confinement.

Effects of strict 105-day isolation on the blood antioxidant status, processes in erythrocyte membranes, and oxygen-binding properties of hemoglobin were studied in six male volunteers (25 to 40 years old) in ground-based simulation of a mission to Mars (Mars-105 experiment). The study was performed with venous blood samples and red blood cells isolated from them, which were collected during the baseline data collection period, on days 35, 70, and 105 of the experiment, and on days 7 and 14–15 after its completion. Biochemical (determination of enzyme activity and thin-layer chromatography) and biophysical (laser interference microscopy and Raman spectroscopy) methods showed changes in the relative content of lipid and phospholipid fractions, suggesting an increase in the membrane microviscosity and the content of TBA-RP (active lipid peroxidation products interacting with thiobarbituric acid). A significant increase in the activity of glucose-6-phosphate dehydrogenase and superoxide dismutase and a reduction in the catalase activity was found, which indicates both reparative processes in red blood cells and imbalance between the amount of generated reactive oxygen species and antioxidant protection mechanisms in cells. The hemoglobin affinity for oxygen and the blood level of oxyhemoglobin also increased. It is assumed that the adaptation of the body to stresses experienced during and after the experiment can disturb the balance between the antioxidant defense systems. The latter, in turn, leads to peroxidation of membrane phospholipids, alteration in their content, increase in membrane microviscosity, and eventual disturbance of the gas-exchange function of red blood cells.

Dynamics of protein spectrum (12 groups of proteins) of the native daily urine was studied by gradient polyacrylamide gel electrophoresis in the experiment on five-day dry immersion in 14 subjects aged from 19 to 26 years. It was established that changes in the level of urinary protein excretion were not observed during the experiment. Nevertheless, the tendency towards formation of a number of shifts in the urinary protein spectrum was found. The excretion of low-molecular-weight proteins was decreased and that of albumin was increased, which reflects the development of tubular reabsorption remodulation under the influence of experimental exposure. The level of Tamm-Horsfall protein was steadily increased, which is likely to be a protective reaction of the body. An incremental reduction of immunoglobulin content in the urine was observed, which is probably related to decreasing permeability of the glomerular filter for high-molecular-weight proteins.

Международный научный эксперимент “Марс-500” позволил за относительно короткие сроки получить большой объём уникальной научной информации о комплексном влиянии факторов межпланетного космического полёта (таких, как автономность существования, задержка связи, международный состав экипажа, наличие в структуре экспедиции кульминационного события – высадки на другую планету) на поведение и деятельность изолированной малой группы. Полученные закономерности обусловливают необходимость внесения изменений в отбор, подготовку и медико-психологическое обеспечение будущего экипажа пилотируемой экспедиции к другим планетам.