[The effect of a two-week anti-orthostatic hypokinesia on the cardiac function and on the latter's regulation in monkeys].

Investigated were the effects of 2-week exposure of four Macaca mulattas to the head-end tilted downward at 10 degrees on contractility of the left myocardium and its controls basing on the data of functional loading tests on the tilting table and at two regimes of centrifugation. The experiment included registration of the left heart pressure, volumetric blood flow in the aorta, and EKG in order to determine stroke volume, maximal isovolumetric pressure, end-systolic and end-diastolic pressures, maximal contraction and relaxation velocities, end-systolic myocardial elasticity, and a constant of the isovolumetric relaxation. As was stated, HDT does not impair contractility of the left myocardium; however, sensitivity of the HR baroreflex control wakens.

[Heart functions in monkeys during a 2-week antiorthostatic hypokinesia].

Dynamics of the left heart ventricular muscle contractility and compliance was studied in 4 monkeys in the head down position (antiorthostatic hypokinesia) with the body angle 10 during 2 weeks. Functional tests on a tilt table and under two conditions of centrifuge rotation were performed prior to and after the antiorthostatic hypokinesia. No changes in the left heart ventricular muscle contractility was found.

[Intracranial pressure in monkeys during the flight of Cosmos-2229].

The paper contains data of the experiment aboard biosatellite Cosmos-2229 which embraced registration of the intracranial pressure (ICP) in primates during space flight. ICP exhibited a small increase (25-30%) comparing with mean values over 20 hours of the prelaunch period and did not go beyond the limits of physiological norm. In the second part of the flight, ICP tended to return to the preflight level.

[Intracranial pressure in monkeys under microgravity].

The results of measurement of the intracranial pressure (ICP) in monkeys on board of the biosatellite "Cosmos-2229" are presented. The ICP grew insignificantly in microgravity. The ICP pulse waveform changed significantly in the first day of the flight but returned to normalcy later.

[The hemodynamics in monkeys during head-down tilt hypokinesia at angles of -6 and -20 degrees].

Hemodynamic changes in the monkeys (2 groups of 3 animals each) during 6 degrees and 20 degrees head down tilts (HDT) of various duration have been studied. An increase of the arterial blood pressure and linear velocity of the blood flow in the common carotid artery was noted immediately after HDT followed by a compensatory decrease of the values. A significant decline in orthostatic tolerance after 20 degrees HDT with developing a precollaptoid state is indicated.