Respiration in conscious dogs at rest and during exercise

Pulmonary and hemodynamic function in dogs during exercise: effects of lung autotransplantation

An airtight facemask/mouthpiece assembly has been devised to facilitate the performance of a wide range of pulmonary function tests during treadmill exercise in dogs. Using this appliance, data were obtained from 6 normal dogs and 3 of the same dogs after left lung autotransplantation. All measurements were made during awake, resting conditions and again after 5-7 minutes of moderate exercise. Resting values for pulmonary function tests, hemodynamic parameters, blood gases and pH from both pulmonary and systemic arterial blood samples did not differ significantly between normal dogs and those studied after left lung autotransplantation. During treadmill exercise, cardiac output doubled and pulmonary vascular resistance decreased comparably in both groups of dogs. Heart rates in both groups rose to approximately 22 b/min and blood gases and pH remained normal. These results indicate the facemask/mouthpiece assembly permits normal ventilation during treadmill exercise. In addition, these data support the view that pulmonary autotransplantation per se need not impose obligatory defects in ventilatory and hemodynamic function despite the increased demands of treadmill exercise.