Effects of selective serotonin and serotonin/noradrenaline reuptake inhibitors on extracellular serotonin in rat diencephalon and frontal cortex
| Autor: | Tommy B. Kang, Sidney B. Auerbach, Stephan Hjorth, Tracy Matthews Felton |
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| Rok vydání: | 2003 |
| Předmět: |
Male
Serotonin medicine.medical_specialty Time Factors medicine.drug_class Injections Subcutaneous Microdialysis Tricyclic antidepressant Venlafaxine Citalopram Pharmacology Imipramine Reuptake Rats Sprague-Dawley Norepinephrine Internal medicine medicine Animals Diencephalon Fluoxetine Adrenergic Uptake Inhibitors Chemistry General Medicine Paroxetine Frontal Lobe Rats Endocrinology Extracellular Space Reuptake inhibitor Selective Serotonin Reuptake Inhibitors medicine.drug |
| Zdroj: | Naunyn-Schmiedeberg's Archives of Pharmacology. 367:297-305 |
| ISSN: | 0028-1298 |
| Popis: | Some clinical reports suggest that tricyclic antidepressants which block both noradrenaline and serotonin (5-HT) reuptake (SNRIs) are more effective than selective 5-HT reuptake inhibitors (SSRIs) in treating severe depression. Moreover, one neurochemical study reported larger increases in extracellular 5-HT in rat frontal cortex in response to the tricyclic antidepressant imipramine compared to the SSRI fluoxetine. However, imipramine, which blocks both 5-HT and noradrenaline reuptake, also binds with relatively high affinity to receptors for noradrenaline, histamine and acetylcholine. Thus, to test the hypothesis that compounds that inhibit both 5-HT and noradrenaline reuptake produce larger increases in 5-HT efflux, we compared the effects of acute systemic administration of several SNRIs and SSRIs. Extracellular 5-HT was measured using microdialysis probes implanted in the diencephalon and frontal cortex of unanesthetized rats. We tested the SSRIs paroxetine (0.3-10 mg/kg), citalopram (10-20 mg/kg) and fluoxetine (10 mg/kg), the nonselective tricyclic antidepressant imipramine (20 mg/kg) and the more selective SNRIs duloxetine (3-30 mg/kg) and venlafaxine (30-50 mg/kg). During the lights-off period, paroxetine and duloxetine increased 5-HT in the diencephalon approximately 300 and approximately 200%, respectively. During the lights-on period, paroxetine and duloxetine each increased 5-HT approximately 400% in the diencephalon. In the frontal cortex, both paroxetine and duloxetine increased 5-HT approximately 200%. Citalopram and venlafaxine each increased 5-HT in the diencephalon approximately 300%. Fluoxetine and imipramine increased 5-HT in the diencephalon by approximately 125 and approximately 80%, respectively. Thus, these results do not support the hypothesis that compared to SSRIs, compounds which inhibit both 5-HT and noradrenaline reuptake have a larger acute effect on extracellular 5-HT. |
| Databáze: | OpenAIRE |
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