Reduction of Blood Flow Through the Hypoxic Lung

Abstract

Individual lung blood flows were measured in the dog by the Fick principle while the lungs were breathing separately through a bronchospirometric catheter. When 1 lung was brought into gaseous equilibrium with the pulmonary arterial blood by rebreathing while the other lung continued to breathe air, half of the animals showed a well-marked shift of pulmonary blood flow toward the air-breathing lung and away from the rebreathing lung. The importance of such a mechanism in man is considered and possible mechanism of its action is discussed. Mean pulmonary arterial and pulmonary venus pressures and pulmonary venus blood O2 content are correlated with the conditions of the expt. Because blood shunting in the lungs was not determined, reinvestigation of this phenomenon in man is warranted.