• Medientyp: E-Artikel
  • Titel: 5‐HT1A agonists increase and 5‐HT3 agonists decrease acetylcholine efflux from the cerebral cortex of freely‐moving guinea‐pigs
  • Beteiligte: Bianchi, Clementina; Siniscalchi, Anna; Beani, Lorenzo
  • Erschienen: Wiley, 1990
  • Erschienen in: British Journal of Pharmacology, 101 (1990) 2, Seite 448-452
  • Sprache: Englisch
  • DOI: 10.1111/j.1476-5381.1990.tb12728.x
  • ISSN: 0007-1188; 1476-5381
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  • Beschreibung: The influence of 5‐hydroxytryptamine1A (5‐HT1A), 5‐HT2 and 5‐HT3 agonists and antagonists on acetylcholine (ACh) release from the cerebral cortex was studied in freely moving guinea‐pigs.8‐Hydroxy‐2‐(di‐n‐propylamino)tetralin (8‐OH‐DPAT, 0.01–1 mg kg−1, s.c.) caused the 5‐HT syndrome and dose‐dependently increased ACh release. Ru 24969 (1–10 mg kg−1, s.c.) shared the same effects, but it was less potent. (−)‐Propranolol (5 mg kg−1) and metitepine (2 mg kg−1) prevented these behavioural and neurochemical responses.(±)‐1(4‐Iodo‐2,5‐dimethoxyphenyl)2‐aminopropane (DOI) up to 2 mg kg−1 did not modify ACh release and ketanserin (0.5 mg kg−1) was ineffective on 5‐HT‐induced changes of ACh outflow.2‐Methyl‐5‐HT (500 μg, i.c.v.) and 5‐HT (500 μg, i.c.v.) plus metitepine (2 mg kg−1, s.c.) inhibited the gross behaviour and ACh release. ICS 205–930 (0.5 mg kg−1) prevented these responses.2‐Methyl‐5‐HT, up to 10 μmoll−1, and 8‐OH‐DPAT, up to 0.1 μmoll−1, (like 5‐HT) did not change [3H]‐choline efflux from cerebral cortex slices.These results suggest that exogenous 5‐HT and related selective agonists modulate guinea‐pig cortical cholinergic structures through 5‐HT1A and 5‐HT3 receptors. The stimulation of 5‐HT1A autoreceptors may lead to disinhibition of the cholinergic cells, tonically inhibited by the tryptaminergic control. Conversely, the stimulation of 5‐HT3 receptors inhibits ACh release, possibly through an interneurone. No direct 5‐HT modulation of the cholinergic nerve endings was found.
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