[Human blood biochemical parameters under the conditions of an arid zone]. / Nekotorye biokhimicheskie parametry krovi cheloveka v usloviiakh aridnoi zony.

Seven participants of 23 day walking march in an arid environment have been examined. Biochemical analysis of blood serum made on Day 2 of marching revealed a decrease in the levels of glucose, triglycerides and an increase in the concentration of non-esterified fatty acids which the authors characterize as the state of moderate stress in an acute period.

[Lipid peroxidation and the system of antioxidant protection in rats following a 13-day space flight on the Kosmos-1887 biosatellite]. / Perekisnoe okislenie lipidov i sistema antioksidantnoi zashchity u krys posle 13-sutochnogo kosmicheskogo poleta na biosputnike "Kosmos-1887".

After a 13-day space mission, in the rats flown on Cosmos-1887 biosatellite the parameters of lipid peroxidation and antioxidant defense system--the contents of diene conjugates, malonic dialdehyde, Schiff bases, tocopherol, total antioxidant activity (in blood plasma only), antioxidant enzyme activity (in tissues only)--superoxide dismutase, catalase, glutathio peroxidase, glutathio reductase have been measured in the blood plasma, myocardium, skeletal muscles and liver. The liver level of diene conjugates, Schiff bases and tocopherol decreased, and an activity of superoxide dismutase and catalase increased. In the skeletal muscles there was an elevation of diene conjugate contents followed by the decreases in malonic dialdehyde and superoxide dismutase activity. In rat myocardium, superoxide dismutase activity and tocopherol levels increased significantly. In the blood plasma the levels of tocopherol, malonic dialdehyde and total antioxidant activity were elevated. It is concluded that the observed changes in lipid peroxidation developed probably in response to an effect of the last dynamic stage of space flight and during re-adapting to the Earth environments.

[Effect of long-term space flight on erythrocyte metabolism and the function of the erythrocyte membrane]. / Vliianie dlitel'nogo kosmicheskogo poleta na metabolizm éritrotsitov i funktsional'noe sostoianie ikh membran.

This paper presents the data about red blood cell metabolism and the structure and function of erythrocyte membranes obtained from two cosmonauts after their 326- and 160-day flights. In both cases we observed inhibition of energy formation (decrease of the rate of glycolysis and ATP content) and enhancement of oxidative processes (decrease of reduced glutathione and activity of antioxidative enzymes). The above changes in the metabolic status of erythrocytes are correlated with shifts at the membrane level, particularly with variations of membrane lipids, phospholipid spectrum and ratios of phospholipid fractions, alteration of membrane-bound enzymes (ATPase) and increase of cell resistance to acid hemolysis. The changes in the erythrocyte membrane leading to lower cell deformability and possible shifts of blood rheological properties give evidence that it is necessary to use preventive membrane stabilization measures at certain flight stages and during readaptation.

[Status of the lipid peroxidation system in the tissues of rats following a 7-day flight on the Kosmos-1667 biosatellite]. / Sostoianie sistemy perekisnogo okisleniia lipidov v tkaniakh krys posle 7-sutochnogo poleta na biosputnike "Kosmos-1667".

Rats flown for 7 days on Cosmos-1667 were for the first time used to measure antioxidative enzymes (superoxide dismutase, glutathione peroxidase, glutathione reductase, catalase), lipid peroxidation products (diene conjugates, malonic dialdehyde, Schiff bases) and tocopherol. Enhanced lipid peroxidation in the heart was completely compensated by activation of antioxidative enzymes. The content of all lipid peroxidation products measured in the liver increased; this was accompanied by a decrease of glutathione peroxidase and an increase of superoxide dismutase activities. It is suggested that lipid peroxidation was activated in response to altered gravity.

[Metabolic characteristics during 120-day head-down tilt hypokinesia]. / Osobennosti obmena veshchestv pri 120-sutochnoi antiortostaticheskoi gipokinezii.

Nine healthy test subjects, aged 25 to 44 years, were exposed to bed rest (at -5 degrees) for 120 days. Venous blood and 24-hour urine samples were used to measure Na, K, total and ionized Ca, Mg, total protein, protein fractions, creatinine, urea, uric acid, malate, isocitric and lactate dehydrogenases, aspartate and alanine aminotransferases, and creatine phosphokinase and its isoforms, acid and alkaline phosphatase and its isoenzymes. Prolonged exposure to head-down tilting resulted in a negative balance of fluid and electrolytes, lowered concentration of total protein and albumins, and an increased concentration of urea and creatinine, basic products of protein metabolism. In blood, the activity of dehydrogenases of the tricarboxylic acid cycle and creatine kinase decreased at the expense of its muscle isoenzyme and the activity of acid phosphatase, total alkaline phosphatase and bone isoenzyme of alkaline phosphatase increased.