Anxiogenic effect of central CCK administration is attenuated by chronic fluoxetine or ipsapirone treatment.
The effect of chronic fluoxetine and ipsapirone treatment on the anxiogenic effect of centrally administered cholecystokinin (CCK) was studied in the social interaction test in male Sprague-Dawley rats. Intracerebroventricular injection of unsulfated CCK-8 significantly decreased total interaction time and locomotor activity and caused some increase in selfgrooming and a reduction in rearing behaviour in a familiar arena in low light conditions. The selective serotonin reuptake inhibitor antidepressant fluoxetine alone (5 mg/kg, i.p.) also had clear acute anxiogenic actions (decrease in total interaction time, locomotor activity, rearing, increase in selfgrooming) after single dosing, but all these effects were omitted after chronic (3 weeks) treatment. In contrast, a single injection of the 5-HT1A receptor partial agonist ipsapirone (5 mg/kg, i.p.) alone had only motor effects (decrease in selfgrooming and rearing), and these effects were preserved after chronic treatment. Chronic fluoxetine treatment (5 mg/kg per day, 3 weeks) abolished the effects of CCK-8 (1 nmol/rat, i.c.v.). Chronic treatment with ipsapirone (5 mg/kg per day, 3 weeks) partially attenuated the effects of CCK-8 (1 nmol/rat, i.c.v.). Our studies provide further evidence for a 5-HT/CCK interaction in the regulation of anxiety.
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Laboratory of Neurochemistry and Experimental Medicine, National Institute of Psychiatry and Neurology, Budapest, Hungary.
Bagdy
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D000818:Animals; D014151:Anti-Anxiety Agents / Q000008:administration & dosage / Q000494:pharmacology*; D000928:Antidepressive Agents / Q000008:administration & dosage / Q000494:pharmacology; D001007:Anxiety / Q000139:chemically induced / Q000503:physiopathology* / Q000517:prevention & control; D002552:Cerebral Ventricles / Q000187:drug effects / Q000502:physiology*; D004334:Drug Administration Schedule; D005473:Fluoxetine / Q000008:administration & dosage / Q000494:pharmacology*; D006120:Grooming; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D011743:Pyrimidines / Q000008:administration & dosage / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology; D012844:Sincalide / Q000008:administration & dosage / Q000494:pharmacology*; D012919:Social Behavior
D014151:Anti-Anxiety Agents; D000928:Antidepressive Agents; D005473:Fluoxetine; D011743:Pyrimidines; D017367:Selective Serotonin Reuptake Inhibitors; D012844:Sincalide; C043077:ipsapirone