Differential regulation of serotonin-1A receptor-stimulated [35S]GTPγS binding in the dorsal raphe nucleus by citalopram and escitalopram

Dania V. Rossi, Teresa F. Burke, Julie G. Hensler

Research output: Contribution to journalArticle

10 Citations (Scopus)

Abstract

The effect of chronic citalopram or escitalopram administration on 5-HT1A receptor function in the dorsal raphe nucleus was determined by measuring [35S]GTPγS binding stimulated by the 5-HT1A receptor agonist (R)-(+)-8-OH-DPAT (1nM-10 μM). Although chronic administration of citalopram or escitalopram has been shown to desensitize somatodendritic 5-HT1A autoreceptors, we found that escitalopram treatment decreased the efficacy of 5-HT1A receptors to activate G proteins, whereas citalopram treatment did not. The binding of [3H]8-OH-DPAT to the coupled, high affinity agonist state of the receptor was not altered by either treatment. Interestingly, escitalopram administration resulted in greater occupancy of serotonin transporter sites as measured by the inhibition of [3H]cyanoimipramine binding. As the binding and action of escitalopram is limited by the inactive enantiomer R-citalopram present in racemic citalopram, we propose that the regulation of 5-HT1A receptor function in the dorsal raphe nucleus at the level of receptor-G protein interaction may be a result of greater inhibition of the serotonin transporter by escitalopram.

Original languageEnglish (US)
Pages (from-to)103-107
Number of pages5
JournalEuropean Journal of Pharmacology
Volume583
Issue number1
DOIs
StatePublished - Mar 31 2008

Fingerprint

Citalopram
Receptor, Serotonin, 5-HT1A
8-Hydroxy-2-(di-n-propylamino)tetralin
Serotonin Plasma Membrane Transport Proteins
GTP-Binding Proteins
Dorsal Raphe Nucleus
Serotonin 5-HT1 Receptor Agonists
Autoreceptors

Keywords

  • [S]GTPγS binding
  • [H]8-OH-DPAT
  • Citalopram
  • Escitalopram
  • Quantitative autoradiography
  • Serotonin-1A

ASJC Scopus subject areas

  • Cellular and Molecular Neuroscience
  • Pharmacology

Cite this

Differential regulation of serotonin-1A receptor-stimulated [35S]GTPγS binding in the dorsal raphe nucleus by citalopram and escitalopram. / Rossi, Dania V.; Burke, Teresa F.; Hensler, Julie G.

In: European Journal of Pharmacology, Vol. 583, No. 1, 31.03.2008, p. 103-107.

Research output: Contribution to journalArticle

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