title: The mechanism of antidepressant-like effects of piroxicam in rats.
abstract: OBJECTIVE
  To investigate the antidepressant-like effect of piroxicam with a focus on serotonergic neurotransmission.
  
  
  METHODS
  Rats were randomly distributed into the following groups: 0.9% saline control; 3 mg/kg pizotifen; 10 mg/kg sertraline; 10 mg/kg piroxicam; 10 mg/kg sertraline + 10 mg/kg piroxicam; 10 mg/kg sertraline + 3 mg/kg pizotifen; and 10 mg/kg piroxicam + 3 mg/kg pizotifen. All the drugs were dissolved in 0.9% saline. Three administrations of the drugs (piroxicam and sertraline) were performed 1, 5 and 24 h before testing the animals in the open field followed by the forced swim test (FST). Piroxicam and sertraline were administered orally by gavage and pizotifen was administered intraperitoneally 30 min before gavage. Immediately after the FST, the hippocampi were rapidly dissected for neurochemical analysis in high-performance liquid chromatography.
  
  
  RESULTS
  Acute treatment with piroxicam promoted an antidepressant-like effect in the FST, which was associated with an increase in serotonin levels in the hippocampus. This effect was potentiated in the piroxicam + sertraline group but counteracted by administration of the non-selective serotonin receptor antagonist pizotifen.
  
  
  CONCLUSIONS
  These results suggest that the antidepressant-like effect of piroxicam in the FST is mediated by the serotonin system; however, by different mechanisms from those of sertraline.
authors.affiliation: Department of Pharmacology, Federal University of Paraná, Brazil.
authors.forename: Ronise Martins
authors.initials: RM
authors.lastname: Santiago
authors.affiliation: Department of Pharmacology, Federal University of Paraná, Brazil.
authors.forename: Tiago
authors.initials: T
authors.lastname: Zaminelli
authors.affiliation: Department of Pharmacology, Federal University of Paraná, Brazil.
authors.forename: Taysa B
authors.initials: TB
authors.lastname: Bassani
authors.affiliation: Department of Pharmacology, Federal University of Paraná, Brazil.
authors.forename: Suelen L
authors.initials: SL
authors.lastname: Boschen
authors.affiliation: Department of Physiology, Federal University of Paraná, Brazil.
authors.forename: Marcelo M S
authors.initials: MM
authors.lastname: Lima
authors.affiliation: Department of Pharmacology, Federal University of Paraná, Brazil.
authors.forename: Cláudio
authors.initials: C
authors.lastname: Da Cunha
authors.affiliation: Department of Pharmacology, Federal University of Paraná, Brazil.
authors.forename: Roberto
authors.initials: R
authors.lastname: Andreatini
authors.affiliation: Department of Pharmacology, Federal University of Paraná, Brazil.
authors.forename: Maria A B F
authors.initials: MA
authors.lastname: Vital
keywords: Depression; forced swim test; piroxicam; serotonin