[The effect of hypothermia and oxygenation on the cardiorespiratory system in man exposed to experimental weightlessness]. / Vliianie okhlazhdeniia i oksigenatsii na kardiorespiratornuiu sistemu cheloveka, nakhodiashchegosia v usloviiakh vozdeistviia faktorov modelirovannoi nevesomosti.

It has been established that hypothermia in experimental weightlessness, as compared to normal conditions, was characterized by a considerably smaller deficit of erythrocytes in the energy balance and reduced gas exchange level, despite unidirectional changes in hemodynamic parameters. Unlike in hypothermia, an increase in oxygen concentration in the inhaled gas mixture had no noticeable effect on the parameters of the cardiorespiratory system studied.

[Metabolic changes in simulated weightlessness]. / Izmeneniia metabolizma pri modelirovannoi nevesomosti.

8 healthy subjects participated in 2 series of experiments on the comparative studies of two techniques of respiratory therapy employing multicomponent anesthesia during controlled lung ventilation in normal conditions and in experimental weightlessness. It has been established that experimental weightlessness, as compared to normal conditions of controlled lung ventilation, was more favourable for the maintenance of effective energy exchange in erythrocytes and tissue O2 consumption. Both techniques of respiratory therapy during controlled lung ventilation are recommended in these conditions.

[Energy metabolism in the erythrocytes of humans exposed to anti-orthostatic hypokinesia]. / Energeticheskii obmen v éritrotsitakh cheloveka v usloviiakh antiortostaticheskoi gipokinezii.

Energy metabolism in red blood cells of men exposed to antiorthostatic hypokinesia (-8 degrees) was investigated. It was found that during this exposure erythrocytes synthesized organic phosphates such as diphosphoglyceric acid (2,3-DPG), ATP and ADP that were similar in terms of their effect on hemoglobin affinity for oxygen. On hypokinesia day 6, when the oxygen concentration in the erythrocyte environment increased, the content of the above phosphates also grew. It can therefore be concluded that glucose metabolism in erythrocytes of test subjects exposed to antiorthostatic hypokinesia is implemented via enhanced interaction between glycolytic and pentose-phosphate pathways.

[Clinico-physiological aspects of the tissue oxygen supply of the human body during head-down tilt hypokinesia]. / Nekotorye kliniko-fiziologicheskie aspekty kislorodnogo obespecheniia tkanei organizma cheloveka v usloviiakh antiortostaticheskoi gipokinezii.

In three antiorthostatic hypokinesia studies of varying duration gas exchange, central and regional hemodynamics were investigated. The hypokinetic effect on oxygen changes in the human body was evaluated by comparing the above results with biochemical data. It is concluded that bed rested subjects developed hypoxic changes of mixed circulatory-respiratory type. When oxygen supply changes drastically under the conditions that were simulated in our study, it is recommended to use oxygen therapy.

[Status of metabolism and peripheral circulation in man during antiorthostatic hypokinesia]. / Sostoianie metabolizma i perifericheskogo krovoobrashcheniia cheloveka v usloviiakh antiortostaticheskoi gipokinezii.

Metabolism and peripheral circulation were investigated in head-down tilt tests of varying duration. The greatest changes were seen on test day 30 when the subjects showed venous hyperoxia, lower oxygen arterio-venous difference and a significant (p less than 0.05) decrease of oxygen tension in arterial blood and oxygen utilization in tissues (p less than 0.05). At the same time the subjects exhibited an increase in Pi and lactate and a maximum growth of 2,3-diphosphoglyceric acid (p less than 0.05). This exposure seems to produce a discrepancy between oxygen supply and oxygen requirements in tissues which gives rise to secondary tissue hypoxia. It is believed that the basic cause of these changes is disordered oxygen transport from blood to tissues.