Release-regulating serotonin 5-HT1D autoreceptors in human cerebral cortex.
Release-regulating 5-hydroxytryptamine (5-HT) autoreceptors in the rat brain belong to the 5-HT1B subtype. On the other hand, the human brain seems to lack 5-HT1B receptors. In the present work 5-HT autoreceptors present in human brain were characterized pharmacologically. Synaptosomes prepared from biopsy samples of human neocortex were labeled with [3H]5-HT and exposed in superfusion to selective 5-HT receptor agonists and antagonists during K+ depolarization. The rank order of potency of agonists as inhibitors of the [3H]5-HT overflow was 5-HT > sumatriptan (5-HT1D/1B) > 8-hydroxy-2-(di-n-propylamino)tetralin (5-HT1A/1D) >> 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane HCl (5-HT2/1C). The effect of 5-HT was insensitive to ketanserin (5-HT2) but antagonized by methiothepin (5-HT1/2) or by metergoline (5-HT1C/1D). The data are compatible with a classification of the human 5-HT autoreceptor as being of the 5-HT1D subtype.
Istituto di Farmacologia e Farmacognosia, Università degli Studi di Genova, Italy.
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Maura
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Thellung
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Andrioli
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Ruelle
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Raiteri
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000328:Adult; D000368:Aged; D002540:Cerebral Cortex / Q000378:metabolism*; D005260:Female; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D011188:Potassium / Q000494:pharmacology; D011985:Receptors, Serotonin / Q000378:metabolism*; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D013449:Sulfonamides / Q000494:pharmacology; D018170:Sumatriptan; D013574:Synaptosomes / Q000378:metabolism*
D007211:Indoles; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D013449:Sulfonamides; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D018170:Sumatriptan; D011188:Potassium