Stroke, Vol 21, 441-446, Copyright © 1990 by American Heart Association
DW Busija and CW Leffler
We examined the chronic and acute effects of perivascular blood on
cerebrovascular responses to norepinephrine and acetylcholine in 35
piglets. In the chronic experiment, fresh autologous blood (n = 15) or
cerebrospinal fluid (n = 14, control) was placed under the dura mater over
the parietal cortex, and the piglets were allowed to recover from
anesthesia. One to 4 days later, a closed cranial window was placed over
the parietal cortex and baseline pial arteriolar responses and responses to
topical application of the neurotransmitters norepinephrine (10(-6) and
10(-4) M) and acetylcholine (10(-4) M) were determined. We also sampled
cerebrospinal fluid from under the window during baseline conditions and
during application of the neurotransmitters, and we measured the
concentrations of prostanoids (6- ketoprostaglandin F1 alpha, thromboxane
B2, prostaglandin F2 alpha, and prostaglandin E2) via radioimmunoassay.
Pial arterioles in the chronic control group (n = 13) constricted by 20 +/-
2% (mean +/- SEM) in response to 10(-4) M norepinephrine and by 28 +/- 2%
in response to 10(- 4) M acetylcholine. In the chronic blood group (n =
14), pial arterioles did not constrict significantly in response to 10(-4)
M norepinephrine but constricted normally (23 +/- 4%) in response to 10(-
4) M acetylcholine. In the acute experiment, six other piglets had blood
placed on the brain surface for 30 minutes and then removed; pial
arterioles constricted by 21 +/- 1% in response to 10(-4) M norepinephrine
(n = 5) and by 28 +/- 4% in response to 10(-4) M acetylcholine (n =
3).(ABSTRACT TRUNCATED AT 250 WORDS)
ARTICLES
Perivascular blood attenuates noradrenergic but not cholinergic effects on piglet pial arterioles
Department of Physiology and Biophysics, University of Tennessee, Memphis 38163.
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