Abstract
Slices from fresh specimens of human neocortex which had to be removed during neurosurgery to reach subcortical tumours were labelled with [3H]-dopamine and stimulated electrically. Quinpirole, a selective dopamine D2 receptor agonist, inhibited the stimulated tritium overflow (EC50 = 25 nM; maximal inhibition: about 80% at 10 microM). The selective D1 receptor agonist, SKF 38393, was inactive up to 10 microM. Quinpirole was antagonized by the D2 receptor antagonist (-)-sulpiride (apparent pA2 = 8.26). Thus dopaminergic axon terminals in the human mesocortical pathway possess autoreceptors of the D2 type.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / pharmacology
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Adult
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Cerebral Cortex / metabolism*
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Cerebral Cortex / physiology
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Dopamine / metabolism
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Dopamine Agents / pharmacology
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Electric Stimulation
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Ergolines / pharmacology
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Female
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Humans
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In Vitro Techniques
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Male
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Middle Aged
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Quinpirole
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Receptors, Dopamine / drug effects
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Receptors, Dopamine / metabolism*
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Receptors, Dopamine D1 / drug effects
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Receptors, Dopamine D1 / metabolism
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Receptors, Dopamine D2 / drug effects
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Receptors, Dopamine D2 / metabolism
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Sulpiride / pharmacology
Substances
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Dopamine Agents
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Ergolines
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Receptors, Dopamine
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Receptors, Dopamine D1
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Receptors, Dopamine D2
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Quinpirole
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2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine
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Sulpiride
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Dopamine