[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. The changes of a circulation pattern in the common carotid artery bed are induced by a cranial shifting of the body fluids.