Stroke, Vol 9, 25-28, Copyright © 1978 by American Heart Association
AN Martins, TF Doyle and S Wright
It has been hypothesized that acute lesions of the brain enlarge through an
autodestructive process. Serotonin (5HT), a potent cerebral
vasoconstrictor, is believed by some to mediate the process by reducing
cerebral blood flow (CBF) in tissue surrounding the lesion. The hypothesis
was tested in cynomologus monkeys anesthetized with ketamine and nitrous
oxide. Craniectomies, 7 mm in diameter, were performed in each parietal
area. The dura was opened and polarographical electrodes of thin platinum
wire were inserted into the parietal lobe cortex of each hemisphere. Mock
cerebrospinal fluid (CSF) was irrigated continously onto the brain
surrounding the electrodes, from which local CBF was determined repeatedly
by the hydrogen-clearance technique. After baseline CBF was established,
solutions of 5HT in mock CSF (in concentrations of 5 X 10(-7) M, 5 X 10(-5)
M, and 5 X 10(-3) M) were irrigated onto one hemisphere while the opposite
hemisphere served as control. 5HT failed to change CBF. Although 5HT is a
potent vasoconstrictor, under physiologic conditions it apparently is
unable to effect hemodynamically significant constriction of the peripheral
cerebral vasculature of the anesthetized monkey brain.
ARTICLES
Effect of topically applied serotonin on local cerebral blood flow
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