AJP - Heart and Circulatory Physiology, Vol 243, Issue 3 442-H447, Copyright © 1982 by American Physiological Society
Responses of cerebral arterioles to increased venous pressure
E. P. Wei and H. A. Kontos
The responses of pial arterioles to increased venous pressure were studied
in anesthetized cats equipped with cranial windows for the observation of
the pial microcirculation. Stable increases in venous pressure consistently
induced arteriolar vasodilation, which averaged 6-12% of the control
diameter. The vasodilation occurred when arterial blood pressure was normal
and during arterial hypotension induced by bleeding; it also occurred
irrespective of whether intracranial pressure was kept constant or was
allowed to increase venous hypertension. The results are consistent with
the view that autoregulatory adjustments in caliber of pial arterioles are
mediated predominantly by metabolic rather than myogenic mechanisms.
