Stimulation of baroreceptors via distention of the pulmonary artery elicits reflex pulmonary hypertension and systemic hypotension, a response that is independent of vagal fibers.
The distention of a large branch of the pulmonary artery, with or without occlusion of the circulation, produces pulmonary hypertension. The occlusion of an entire hilum, without adequate stimulation of the arterial baroreceptors produces only a negligible increase in pulmonary arterial pressure. Together with the pulmonary hypertension, variable changes in the systemic pressure were observed. The most frequent reaction was hypotension. The vagal fibers play no role in the pulmonary hypertensive response.
Osorio et al. (Sun,) studied this question.
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