[Characteristics of the central regulation of venous vessels]

In acute experiments on cats, the magnitude and type of responses of hindlimb accumulating vessels and of those responsible for pressure stabilization, to pressor reflexes were studied under normal conditions of the vasomotor center and after brain sections at different levels (decortication, decerebration, spinalization) as well as after occlusion of femoral or cava posterior vein. A considerable increase of arterial vessels responses to pressor reflexes occurred after decerebration at the intercollicular level whereas occlusion of the femoral or cava posterior veins led to a significant decrease of the responses. The reactions of venous vessels were constant owing to the specific features of their central regulation. Only efferent impulses to arterial part of the vascular bed seem to change under these conditions while modification of "venous" part of the efferent patterns occurred, probably, at the spinal cord level.