The antidepressant drugs fluoxetine and duloxetine produce anxiolytic-like effects in a schedule-induced polydipsia paradigm in rats: enhancement of fluoxetine's effects by the α2 adrenoceptor antagonist yohimbine. Issue 5 (August 2015)

• Record Type: Journal Article
• Authors: Prus, Adam J.; Mooney-Leber, Sean M.; Berquist, Michael D.; Pehrson, Alan L.; Porter, Nicholas P.; Porter, Joseph H.
• Is Part Of: Behavioural pharmacology. Volume 26:Issue 5(2015)
• Publication Date: 2015-08
• Subjects: adrenergic receptor -- antidepressant -- anxiety -- anxiolytic model -- polydipsia -- rat; Psychopharmacology -- Periodicals; Nervous System -- drug effects -- Periodicals; Behavior -- drug effects -- Periodicals; 615.78
• DOI: 10.1097/FBP.0000000000000159
• Languages: English
• ISSNs: 0955-8810

Abstract

Abstract : Similar to the time-course for treating depression, several weeks of administration are required for serotonin (5-HT) reuptake inhibitors to produce anxiolytic effects. Previous studies with the schedule-induced polydipsia paradigm (a putative preclinical anxiety model) have shown that repeated administration of antidepressant drugs is necessary to produce a suppression of polydipsia, which is interpreted as an anxiolytic-like effect. The present study sought to expand past findings by evaluating the selective 5-HT reuptake inhibitor (SSRI) fluoxetine and the 5-HT-norepinephrine reuptake inhibitor duloxetine in the schedule-induced polydipsia paradigm with rats. Dose combinations of the α2 adrenoceptor antagonist yohimbine with fluoxetine were also explored to determine whether α2 adrenoceptor antagonism could enhance the anxiolytic-like effects produced by an SSRI. Fluoxetine and duloxetine significantly reduced water intake over the course of daily administrations. Daily treatment with the combination of fluoxetine and yohimbine produced a significantly greater reduction in water intake than fluoxetine alone. The present results confirmed previous findings that inhibition of 5-HT reuptake reduces water consumption in this paradigm. The results for the α2 antagonist yohimbine (in combination with fluoxetine) also indicate that α2 adrenoceptor antagonism may significantly enhance anxiolytic-like effects of SSRIs.