[Effectiveness of anti-G devices of the nonchamber type after head-down tilt hypokinesia lasting up to 7 days]. / Issledovanie éffektivnosti protivoperegruzochnykh ustroistv beskamernogo tipa posle ANOG prodolzhitel'nost'iu do 7 sut.

In three experimental series in which 34 male test subjects (aged 20 to 31 years) participated, acceleration tolerance (+Gz) was measured before and after exposure to 7-day head-down tilting. The measurement tests were performed using an antigravitational device in two modifications AGU-1 and AGU-2. After tilting, tolerance to sustained acceleration +Gz decreased significantly. The use of the device helped to increase acceleration tolerance, AGU-1 all the test subjects tolerated acceleration up to 4.0 G while in AGU-2 only up to 3.0 G. The use of the AGU device following exposure to antiorthostatic hypokinesia helped to maintain the high quality of operator's activities as compared to the controls.

[Various reactions of the human body during 7 days of anti-orthostatic hypokinesia]. / Nekotorye reaktsii organizma cheloveka v usloviiakh semisutochnoi antiortostaticheskoi gipokinezii.

Time-course variations in the cardiovascular parameters, vestibulo-autonomic stability, work capacity and nutritional status were measured in 20 male test subjects, aged 19-22, who were exposed for 7 days to head-down tilt (-10 degrees). Beginning with days 3 or 4, new hemodynamic ratios developed that indicated a new level of circulation regulation and adaptation to head-down tilt. It appears that blood redistribution towards the head led to an enhanced vestibulo-autonomic stability. Renal excretion of nitrogen increased, reaching the highest level on days 6-7. The investigations allow the conclusion that 7-day head-down tilt may cause changes in almost every physiological system.

[Effect of hypokinesia and +Gz loads on the transport function of blood in man]. / Vliianie gipokinesii i peregruzok +Gz na transportnuiu funktsiiu krovi cheloveka.

The results of 44 studies of circulation parameters and blood transport function of 14 test subjects exposed to 7-day bed rest (-10 degrees head-down tilt) and acceleration -4.5 Gz have demonstrated that the blood transport carriers and their actively binding centers form working structures in the adaptive reactions. As compared to the pretest level, the distribution ratio of 14C-adenine between two immiscible phases (plasma/oil, erythrocytes/oil) varies from -12 to 14% on bed rest day 3 to +32 to 40% on bed rest day 7; it increases by 145-150% after exposure to acceleration +4.5 Gz. The parameters of the blood transport function give a quantitative description of its adaptive reactions to environmental effects.

[Possibilities of preventing the adverse reactions in modeling the acute period of adaptation to weightlessness]. / Nekotorye vozmozhnosti profilaktiki neblagopriiatnykh reaktsii pri modelirovanii ostrogo perioda adaptatsii k nevesomosti.

It has been shown that during head-down tilting at an angle of -30 degrees occlusion of the four limbs by 70 mm Hg relieved unpleasant symptoms. According to rheoencephalography, cerebral blood flow decreased to the level normally seen in the supine position. During a prolonged head-down tilting at an angle of -15 degrees intermittent occlusion of only lower limbs by 60--30 mm Hg proved more effective.