Factors Influencing Pulmonary Hypertensive Response to 5-Hydroxytryptamine
The pulmonary hypertensive response to 5-HT in the dog heart-lung preparation is largely due to pulmonary vasoconstriction. There is an unexpected fall in aortic blood flow but no rise in left atrial pressure. In intact dogs the pulmonary hypertensive response is accompanied by an increase in pulmonary blood flow which is in turn partly reduced by upper thoracic sympathectomy. It is suggested that the rise in pulmonary blood flow is partly a sympathetic reflex initiated by pulmonary vasoconstriction by 5-HT.
- Received April 18, 1962.
- © 1962 American Heart Association, Inc.