Stroke, Vol 15, 666-671, Copyright © 1984 by American Heart Association
LA Newberg, PA Steen, JH Milde and JD Michenfelder
Ten minutes of cerebral ischemia was produced in 12 dogs by temporary
ligation of the venae cavae and aorta. After reperfusion the dogs received
the calcium entry blocker, flunarizine, 6 micrograms/kg infused over a ten
minute period. Cerebral blood flow (CBF) and metabolism (CMRO2) were
measured pre-ischemia and for 2 h post-ischemia in 6 dogs. At the end of
the study brain biopsies were analyzed for cerebral metabolites. Neurologic
recovery was evaluated for up to 48 h post-ischemia in an additional 6
dogs. The results of each study were compared to those previously obtained
in untreated animals. The cerebral blood flows (when expressed as a percent
of the pre-ischemic control value) of the flunarizine-treated and untreated
groups were similar throughout the post-ischemic period. Following an
initial hyperemia, the CBF fell to significantly less than the pre-ischemic
control values, and remained approximately 26% of control during the final
90 min in both groups. The CMRO2 was also the same for both groups.
Cerebral metabolites were similar although abnormal in both groups.
Flunarizine produced pulmonary edema in 5 of 6 dogs studied for neurologic
recovery. Four of these dogs died within 12 h and another dog demonstrated
severe neurologic damage. None of the untreated dogs developed pulmonary
edema, but 6 of 7 dogs evidenced severe neurologic damage or were dead at
48 h. Thus, flunarizine failed to improve either cerebral blood flow or
neurologic outcome when given after complete cerebral ischemia in the dog.
A cardiodepressive effect of flunarizine might have contributed to the poor
neurologic outcome.(ABSTRACT TRUNCATED AT 250 WORDS)
ARTICLES
Failure of flunarizine to improve cerebral blood flow or neurologic recovery in a canine model of complete cerebral ischemia
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