These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Effects of acute and repeated administration of antidepressant drugs on extracellular levels of 5-hydroxytryptamine measured in vivo.
    Author: Kreiss DS, Lucki I.
    Journal: J Pharmacol Exp Ther; 1995 Aug; 274(2):866-76. PubMed ID: 7636750.
    Abstract:
    Extracellular levels of serotonin (5-HT) and the regulation of 5-HT release by the 5-HT1A receptor were examined after single and repeated treatment with different types of antidepressant drugs: the selective 5-HT uptake inhibitor fluoxetine, the selective norepinephrine uptake inhibitor desipramine and the 5-HT2A/2C/alpha 2 receptor antagonist mianserin (each at 15.0 mg/kg). Extracellular levels of 5-HT were measured using in vivo microdialysis in the striatum and hippocampus of rats anesthetized with chloral hydrate. Acute administration of fluoxetine transiently elevated the levels of 5-HT in the striatum and hippocampus; desipramine did not change 5-HT levels, and mianserin slightly decreased 5-HT levels in the hippocampus. Rats were administered these antidepressant drugs for either 1 or 14 days and studied 48 hr after the final injection. Repeated treatment with fluoxetine increased base-line levels of 5-HT in the striatum and hippocampus; repeated treatment with desipramine increased base-line 5-HT levels in the striatum only, and repeated treatment with mianserin did not alter base-line 5-HT levels. Repeated fluoxetine treatment attenuated the ability of the 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) to decrease 5-HT release in both the striatum and hippocampus. Repeated desipramine treatment did not significantly alter the effects of 8-OH-DPAT on 5-HT release, but there was a hint of a decreased effect in the hippocampus. Repeated mianserin treatment did not significantly alter the effects of 8-OH-DPAT on 5-HT release, but there was a hint of an increased effect in the striatum. The results of the present study suggest that repeated treatment with antidepressant drugs alters extracellular levels of 5-HT and the ability of 5-HT1A receptors to regulate the release of 5-HT in a regionally selective manner. These changes in the regulation of 5-HT release produced by antidepressant drugs may be associated with their therapeutic effects, because they are caused by repeated rather than acute treatment.
    [Abstract] [Full Text] [Related] [New Search]