Pulmonary blood volume in experimental unilateral pulmonary-artery occlusion.

THE behavior of the vascular bed appears to be contradictory. A number of papers indicate that the pulmonary circulation in man shows slight variations in arterial pressure during muscular exercise," after pulmonary resections" or following the occlusion of a main branch of the pulmonary artery." Conversely, other experimental and clinical studies appear to demonstrate that the pulmonary vascular tree is a practically rigid system." This report pertains to the effects of the ligation of a main branch of the pulmonary artery, on blood flow, blood volume and vascular pressures for the pulmonary circulation of anesthetized dogs.