Respiratory Response to Partial Occlusion of the Main Pulmonary Artery in the Dog

Abstract

By means of an adjustable clamp, which was placed about the pulmonary artery and led through the chest wall, pulmonary blood flow was controlled in the trained, unanesthetized dog. Temporary constriction of the pulmonary artery produced a rise of central venous pressure, a drop of mean arterial blood pressure and hyperpnea and tachyp-nea. Respiratory response to a restriction of pulmonary blood flow was found to be dependent upon the drop of mean arterial blood pressure and independent of the rise in central venous pressure. A reduction of cerebral blood pressure equal to that produced by pulmonary artery constriction did not elicit the described respiratory response.