Abstract
Local cerebral blood flow was measured in anaesthetized beagle dogs by the hydrogen clearance method. Dopamine was administered as a continuous intravenous infusion of varying doses. The changes in local cerebral blood flow induced by dopamine were similar at the different locations; i.e., the caudate nucleus, thalamus, frontal and parietal cortex. Blood flow responded to dopamine in the following ways: low dose (< 2 μg/kg/min): blood flow decreased or remained unchanged; moderate doses (2-6 μg/kg/min): blood flow increased at all electrodes; high doses (7-20 μg/kg/min): blood flow decreased once again. The decrease in blood flow could be inhibited by the alpha-adrenergic receptor antagonist phentolamine or by the serotonin receptor antagonist methysergide. This indicates that the constrictor effect of dopamine on cerebral blood vessels is mediated via alpha-adrenergic receptors as well as via serotonin receptors. The increase in cerebral flow could be inhibited by the dopamine receptor antagonist haloperidol, indicating vascular dopamine receptors in the brain with a dilating effect. When the vasoconstrictor activity of dopamine is blocked, the single response to a dopamine infusion is a blood flow increase. This might be beneficial in the clinical situation of symptomatic vasospasm.
Original language | English (US) |
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Pages (from-to) | 181-188 |
Number of pages | 8 |
Journal | Surgical Neurology |
Volume | 13 |
Issue number | 3 |
State | Published - 1980 |
All Science Journal Classification (ASJC) codes
- Surgery
- Clinical Neurology