Stroke, Vol 7, 239-243, Copyright © 1976 by American Heart Association
DD Heistad and ML Marcus
The concept that reflex control of cerebral vessels is unimportant has been
challenged by recent studies which suggest that carotid baroreceptors have
an important role in regulation of cerebral blood flow (CBF). In this study
we have tested the hypothesis that arterial baroreceptors contribute to
regulation of total or regional CBF. CBF was measured in anesthetized dogs
with 15 mu microspheres. Stimulation of carotid baroreceptors, by raising
carotid sinus pressure, did not alter or redistribute cerebral flow.
Responses to baroreceptor stimulation were intact, as manifested by
vasodilation in skeletal muscle. CBF decreased during systemic hypocapnia
and increased during hypercapnia, which indicates that failure of cerebral
flow to change during baroreceptor stimulation was not due to
unresponsiveness of cerebral vessels. During hypercapnia, baroreceptor
stimulation also failed to alter CBF. In other studies CBF was measured
during increases in systemic arterial pressure, before and after
denervation of arterial baroreceptors. Increases in arterial pressure did
not increase CBF either before or after denervation of baroreceptors. We
conclude that baroreceptor stimulation does not alter total or regional CBF
and that baroreceptors do not regulate cerebral flow during systemic
hypertension.
ARTICLES
Total and regional cerebral blood flow during stimulation of carotid baroreceptors
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