[A comparative study of external respiration, gas exchange and circulation during static and dynamic muscular loads]. / Sravnitel'noe issledovanie vneshnego dykhaniia, gazoénergoobmena i krovoobrashcheniia pri staticheskoi i dinamicheskoi myshechnykh nagruzkakh.

Indices of external breathing, gas exchange, and circulation were studied during bicycle ergometry and static ergometry of 19 healthy male volunteers which were stopped at critical levels of heart rate, arterial pressure, ECG or subjective fatigue. The bicycle workload maximum averaged 210 Watts, the static ergometric, 224 kg/s. Both types of exercises were characterized by unidirectional shifting of the external breathing and gas exchange indices; however, they were less pronounced at static loads. Arterial pressure and resistance of the peripheral vessels were the only indices of the array the dynamics of which complied with and even exceeded that during bicycling. In contrast to the dynamic muscular load, the maximal dynamics of gas exchange and external breathing during static ergometric workload was observed in the rehabilitation period following restoration of muscle blood flow; this must be taken into account in interpretation of test results. It is concluded that high information virtues of the static ergometric test in the context of predicting aerobatic load tolerance, and similarity of dynamics in the period of rehabilitation hold much promise for using the tests with static muscular loading in aviation and space medicine.

[Dynamics of the redistribution of human blood in response to lower body negative pressure]. / Dinamika pereraspredeleniia krovi u cheloveka pri sozdanii ponizhennogo davleniia nad nizhnei polovinoi tela.

During exposure to LBNP of -10 to -60 mm Hg variations in the blood filling of body segments were measured, using 59Fe labelled erythrocytes. The study was performed on 10 healthy volunteers each of which was exposed to six LBNP sessions (in recumbency). The data obtained were related to changes in the blood filling of various body segments (head, thorax, abdomen, pelvis, legs) which were most pronounced at LBNP -20 to -30 mm Hg. As the LBNP level increased, the changes in the blood filling of the pelvis and legs, head and thorax decreased. In the abdominal area this parameter remained essentially unaltered. The distinct variations in the thoracic blood filling were probably dependent on the amount of blood shifted to the decompressed area which may be related not only to the venous capacity in this area but also to the venous- arterial reflexes and possibly to the specific transfer of reduced pressure in tissues.