Stroke, Vol 15, 527-530, Copyright © 1984 by American Heart Association
TA McCalden, RG Nath and K Thiele
In vitro studies suggest that cerebrovascular contraction is more dependent
on the influx of calcium to smooth muscle than general systemic arteries.
The present study tested the in vivo effects of a calcium influx blocker
(nimodipine) on cerebral blood flow and metabolism in 16 baboons. The
133xenon clearance technique was used together with careful control of EEG
and blood gases. With normal blood gases intravenous nimodipine infusion (1
microgram/kg/min) produced an 18% increase in cerebral blood flow with no
alteration in cerebral oxidative metabolism or blood pressure. Higher doses
(above 10 micrograms/kg/min) resulted in a decreased arterial blood
pressure and a return to control cerebral flow. Infusion of the dose
producing maximal increase in flow, decreased the cerebral reactivity to
altered PCO2 (n = 5). These results suggest that nimodipine may be a
relatively selective cerebrovascular dilator.
ARTICLES
The effects of a calcium antagonist (nimodipine) on basal cerebral blood flow and reactivity to various agonists
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