Pulmonary Vasomotor Responses to Epinephrine and Norepinephrine in the Cat
Influence of the Sympathetic Nervous System
Constant intravenous infusion of epinephrine has no effect on the pulmonary vascular resistance (P.V.R.) of the cat under chloralose anesthesia, either when the chest is opened and artificial ventilation is used, or when the animal is respiring naturally. The same dose of epinephrine given after removal of the stellate ganglia and upper 4 to 5 thoracic sympathetic ganglia, can cause an increase of P.V.R. Removal of such ganglia causes a decrease of P.V.R. Electrical stimulation of the cardiac branches from both stellate ganglia causes either an increase or a decrease of P.V.R. Increases of P.V.R. have been produced by intravenous infusion of norepinephrine.
- Received February 3, 1960.
- © 1960 American Heart Association, Inc.