[Studies of red blood cells biochemistry and erythropoiesis intensity in humans during the 520-day isolation study].

Erythrocyte metabolism and erythropoiesis intensity were investigated in the humans subjects (6 males, 25 to 37 yrs. of age) volunteered for experimental simulation of such factors in a mission to Mars as very long duration (520-d) of isolation and confinement, autonomy, delayed communication, emergencies, and limited consumable resources. Venous blood and extracted erythrocytes were analyzed in the baseline data collection period (2 wks. before the experiment), on days 60, 120, 170, 240, 300, 360, 417 and 510 of the experiment and on days 7-8 after its completion. Erythrocyte metabolic and plasmatic membrane parameters were measured. Blood serum was analyzed for iron turnover; erythropoiesis intensity was evaluated by the erythropoietin level. According to the results of the investigation, there were phase-type shifts in the parameters throughout the experiment that were particularly significant on days 60 and 120. Inhibition of energy-production and enhancement of reparative processes in the cell could be tokens of compensatory reactions aimed to control oxidation processes and to raise antioxidation efficiency of the cell. The phase-type changes in membrane lipids and phospholipids point to increased microviscosity of the plasmatic membrane at the beginning and then end of the experiment. Hemoglobin content in blood and erythrocytes showed a significant increase on day-510 of isolation and in the ensuing recovery period. Data about iron turnover and erythropoietin level evidence an adequate bone marrow response to the changed hemoglobin content in blood.

[Studies of the blood antioxidant system and oxygen-transporting properties of human erythrocytes during 105-day isolation].

Effects of strict 105-d isolation on blood antioxidant status, erythrocyte membrane processes and oxygen-binding properties of hemoglobin were studied in 6 male volunteers (25 to 40 y.o.) in ground-based simulation of a mission to Mars (experiment Mars-105). The parameters were measured using venous blood samples collected during BDC, on days 35, 70 and 105 of the experiment and on days 7 and 14-15 after its completion. Methods of biochemistry (determination of enzyme activity and thin-layer chromatography) and biophysical (laser interference microscopy, Raman spectroscopy) showed changes in relative content of lipid and phospholipid fractions suggesting growth of membrane microviscosity and increase in TBA-AP (active products of lipids peroxidation interacting with thiobarbituric acid). A significant increase in glucose-6-phosphate dehydrogenase and superoxide dismutase activities against reduction of catalase activity points to both reparative processes in erythrocytes and disbalance between the number of evolving active forms of oxygen and antioxidant protection mechanisms in cells. Hemoglobin sensitivity of oxygen and blood level of oxyhemoglobin were found to increase, too. It is presumed that adaptation of organism to stresses experienced during and after the experiment may destroy balance of the antioxidant protection systems which is conducive to oxidation of membrane phospholipids, alteration of their content, increase of membrane microviscosity and eventual failure of the gas-exchange function of erythrocytes.

[Examination of the morphofunctional properties of red blood cells of humans in 5-day dry immersioin].

Blood of six normal male volunteers sampled before, immediately after and in 7 days since 5-d dry immersion was analyzed for morphological parameters, erythrocyte metabolism, lipids and phospholipids levels. The experimental exposure was shown to increase the erythrocyte count. Also, upward trends were displayed by hemoglobin and PCV on the first day after the experiment; a significant decrease in adenosine triphosphate and low level of reduced glutathione could be an outcome of enhanced oxidation in cell due to, maybe, LPO activation. There was a downward trend in the phospholipids fraction of erythrocyte membrane against steady levels of cholesterol and its ethers which might be linked with the reliable growth of the fraction of nonesterified fatty acids on day 1 and triglycerides on days 1 and 7 post the experiment.

[Investigations of the morphofunctional properties of red blood in human subjects during 9-day exposure in oxyargon medium with various oxygen content].

Biochemical investigations of red blood and oxygen transportation by erythrocyte hemoglobin were performed in volunteered for chamber experiments (0.14 MPa) with normal and hypoxic oxyargon medium (O2-Ar). Erythrocyte metabolism, lipid and phospholipids spectra, and effectiveness of oxygen release and retention by hemoglobin were studied in the baseline data collection period, on day 6 in hyperbaric and normoxic O2-Ar medium (13.7% O2), on day 3 in hyperbaric and hypoxic O2-Ar (9.9% O2) and on day 1 and 10 during the post-experiment rehab. Elevated pressure, hypoxia and ensuing decompression revealed an ATP reduction that could be a result of shifts on the membrane level and increased G6PD activity associated with cell reparation processes. Changes in membrane lipid and phospholipids composition point to an altered phase state of plasmatic membrane, i.e., increased viscosity which is indicative of possible impairment of membrane permeability As a rule, hyperbaria impacted oxygen transportation in blood of the subjects; effect of hypoxia combined with hyperbaria was not uniform ranging from none to decreasing or increasing oxygen transportation that can be extenuated by selectivity and individual sensitivity to the factors in the experiment Loss of O2 transportation efficiency by hemoglobin is most likely connected with the increase of plasmatic membrane viscosity that could affect hemoporphyrin conformation of membrane-bound hemoglobin and obstruct oxygen transport though membrane.

[Role of viscosity and permeability of erythrocyte plasmatic membrane in controlling the oxygen transport effectiveness by human hemoglobin on completion of space flight].

Plasmatic membrane viscosity and permeability and hemoporphyrine conformation in human hemoglobin were studied on completion of long-duration space flight (LSF). Reversible increases in viscosity and selective permeability (Na+/H+ -turnover) of erythrocyte plasmatic membrane were observed immediately after and in the period of recovery from LSF. Viscosity of lipids in both external and internal locations of plasmatic membrane in human erythrocytes was changed after LSF. The reversible rise of the Na+/H+ -turnover is likely to alter intracellular pH and oxygen binding with hemoglobin. The former is confirmed by the concurrent reversible decline in the deoxyhemoglobin ability to bind oxygen and the oxyhemoglobin ability to retain oxygen. In LSF and during readaptation to the normal gravity blood levels of hemoglobin and free iron are known to be reduced and may be answerable for the hypoxic state of human organism.

[Red blood of cosmonauts on missions aboard the International Space Station (ISS)].

Morphobiochemical investigations of red blood (space experiment Hematologiya) involved the ISS Russian crew members (increments 6-12). Blood samples were drawn on L-30, at the beginning (FD 6-10) and end (FD 160-190) of orbital flight, shortly after landing (R+0), and on R+7 and R+15. Results of the investigations of red blood metabolism and cell membrane showed that long-duration space flight reduces the hemoglobin level in consequence of, probably, intensive erythropoiesis and premature partial elimination of degraded (possibly old) erythrocytes from circulating blood. High intensity of erythropoises is manifested by an increase in erythropoietin, a decrease in blood iron, and elimination of degraded and old erythrocytes in the course of readaptation to Earth and driven by the growing body demand for oxygen to support muscular work and existence in the gravitational environment in general.

[Morphobiochemical assay of the red blood system in members of the prime crews of the International Space Station].

According to the experiment Hematology protocol, blood samples from the Russian members of ISS prime crews 1 to 5 were gathered on L-30 and R+0, 7, 15 to study metabolic parameters (ATP, reduced glutathione, LHG and glucose-6-phosphate dehydrogenase activities). Lipid spectrum of membrane erythrocytes was determined in frozen erythrocyte mass; iron turnover and erythropoietin were investigated in frozen serum. Ratios of different erythrocyte forms were established in 32 microl of fixated whole blood using scanning electron microscopy. On R+0, the morpho-biochemical parameters of red blood appear to still carry the imprints of space effects and, to an extent, certain difference in the setting of blood sampling from the Mir crew on landing in the space "shuttle" vehicle. Low level of iron and significantly increased erythropoietin on R+0 are the testimony of intensive hemoglobin production and an adequate bone morrow response to the increased oxygen demand. Shifts in erythron are of no clinical implications but indicative of the red blood adaptation to the factors of space fight.

[Effects of UV-radiation on metabolism and structural-functional status of the rat's erythrocyte membranes].

In-vitro analysis of venous blood taken from rats irradiated by 300 and 5,000 J/m2 of UV showed no effect on metabolism and, therefore, energy and recovery systems of erythrocytes. Concentrations of 2,3-diphosphoglycerate and reduced glutathione were increased after irradiation by 5,000 J/m2. UV-irradiation at 10,000 J/m2 decreased adenosine triphosphate and phospholipids in blood and impaired the functional stability of erythrocyte membranes. Recovery of the membrane structure in 24 hrs. after irradiation suggests extended photochemical processes in cells and is consistent with the literary data about indirect effects of plasma proteins on the red cell function.

[The red blood system in men during long-term head-down bed rest].

Red blood was analyzed in six 25 to 40 yr. old male volunteers in a 120-d head-down bedrest (HDBR) study. The hematological investigation included morphological analyses (erythrocyte count and hemoglobin), and determination of iron turnover, erythrocyte IgA, IgG and IgM, metabolism, lipids and phospholipids, and lipid peroxidation rate (LPO). At the beginning of HDBR (day 7), the erythrocyte count and hemoglobin content were found increased w/o any visible changes in the other parameters. Further exposure to HDBR (days 50-100) resulted in modification of intracellular metabolism in erythrocytes, increases in serum iron, and serum and erythrocyte ferritin. On HDBR days 50 and 100, and post-HDBR day 9, cholesterol was increased, LPO intensified and antioxidant activities inhibited, which suggested destabilization of the cell membrane. Hematological shifts in the bedrested volunteers were of the type and pattern similar to those in cosmonauts who fulfilled extended space missions.

[Hematological investigations in conditions of long-term space flights]. / Gematologicheskie issledovaniia v usloviiakh dlitel'nykh kosmicheskikh poletov.

In the nearly 15-month mission aboard MIR the cosmonaut-physician and members of three crews (MIR-15, -16, and -17) carried out a program of hematological investigations. Most of the changes related to the red blood system and included reduction in hemoglobin and hematocrit. Erythrocytes had decreased concentration and took on abnormal forms. There were also signs of altered metabolism of erythrocytes. Of interest are phase-by-phase variations in the levels of erythrocytes in the course of long-term stay in microgravity, and absence of a convincing correlation between hemoglobin, erythrocyte and hematocrit levels. But for lymphocytosis that returned to the norm already on the first day of recovery, no material changes occurred to the leukocyte profile. Investigations at the landing site displayed erythropenia, decreased reticulocytes and ensuing reticulocyte reaction, and gradual regain of the erythrocyte number that can be viewed as a normal physiological reaction of the blood system to the set of factors of spaceflight and early readaptation. Besides, the investigations showed a large individually of blood reactions to prolonged stay in space flight.

[Influence of space flight factors on peripheral red blood cells in humans]. / Vliianie faktorov kosmicheskogo poleta na perifericheskuiu krasnuiu krov' cheloveka.

Investigations of cosmonauts' peripheral red blood prior to and on days 1, 7 and 14 post long-term MIR-19 and -20 missions dealt with the morphological composition of blood, indices of iron exchange, correlation of erythrocyte shapes, and the lipid and phospholipid profiles of the erythrocyte membrane. To this avail, methods of light electron microscopy, radioimmune analysis, and thin-layer microscopy were used. Among the unidirectional shifts in the crewmembers of these missions were changes in ion exchange indices and the lipid and phospholipid profiles of erythrocyte membrane which were indicative of increased microviscosity of the lipid layer. Number of erythrocytes and hemoglobin content were reduced; transformed erythrocytes were present. It was also discovered that the fraction of normal erythrocytes (diskocytes) was partially replaced by spherocytes, cnisocytes in flight and typically by echinocytosis post flight. By and large, the observed shifts do not have any clinical implications and are most likely the blood system reaction to the stress of readaptation to the terrestrial conditions.