[The effect of gravitational stress in the pelvis--head direction on the blood vessels of the sympathetic trunk].

The experiment was carried out in 15 rabbits. Three of them were control. The stress of the pelvis--head direction was obtained in a centrifuge of 1 m radius. Six animals were rotated for 1 min., the other six--til death, which came within 3--4,5 min. of the experiment. By methods of injection, clearing and measuring it was found that in the vessels of the sympathetic trunk congestion phenomena were first and foremost under effects of stresses of the caudo-cranial direction. Their intensity is in direct dependence on the duration of stress. In the 1st series (1 min.) a considerable congestion of venous blood in the cranial sympathetic ganglion was observed in 1 case, while in the 2nd series (3--4,5 min.) very drastic congestion phenomena, with an enlarged diameter, vein deformity and so on, were constantly noted. A support is given to literature data that such "negative" stresses are less endurable for animals, death comes soon, since the phase of relative compensation under given conditions is promptly changed for the phase of decompensation.